Properly handle SyntaxContext of dummy spans in incr comp

[Aaron1011]

Fixes #80336

Due to macro expansion, we may end up with spans with an invalid
location and non-root SyntaxContext. This commits preserves the
SyntaxContext of such spans in the incremental cache, and ensures
that we always hash the SyntaxContext when computing the Fingerprint
of a Span

Previously, we would discard the SyntaxContext during serialization to
the incremental cache, causing the span's Fingerprint to change across
compilation sessions.

[rust-highfive]

r? @ecstatic-morse

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[Aaron1011]

This is analogous to #76658, but for incremental compilation instead of crate metadata.

[Aaron1011]

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

[bors]

⌛ Trying commit 84698d487ab2dfff21532a295f0e3f8d27051a8c with merge ac3a3578dcd48df9fc31b9f98a2e687e61b70965...

[bors]

☀️ Try build successful - checks-actions
Build commit: ac3a3578dcd48df9fc31b9f98a2e687e61b70965 (ac3a3578dcd48df9fc31b9f98a2e687e61b70965)

[rust-timer]

Queued ac3a3578dcd48df9fc31b9f98a2e687e61b70965 with parent bcd6975, future comparison URL.

@rustbot label: +S-waiting-on-perf

[rust-timer]

Finished benchmarking try commit (ac3a3578dcd48df9fc31b9f98a2e687e61b70965): comparison url.

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. Please note that if the perf results are neutral, you should likely undo the rollup=never given below by specifying rollup- to bors.

Importantly, though, if the results of this run are non-neutral do not roll this PR up -- it will mask other regressions or improvements in the roll up.

@bors rollup=never
@rustbot label: +S-waiting-on-review -S-waiting-on-perf

[wesleywiser]

r? @wesleywiser

[wesleywiser]

@bors r+

[bors]

📌 Commit 84698d487ab2dfff21532a295f0e3f8d27051a8c has been approved by wesleywiser

[bors]

⌛ Testing commit 84698d487ab2dfff21532a295f0e3f8d27051a8c with merge 134ca574fc359f19ae3824c18b846c0f38e056de...

[rust-log-analyzer]

The job wasm32 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

failures:

---- [incremental] incremental/issue-80336-invalid-span.rs stdout ----

error in revision `rpass1`: compilation failed!
status: exit code: 1
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/incremental/issue-80336-invalid-span.rs" "-Zthreads=1" "--target=wasm32-unknown-emscripten" "--cfg" "rpass1" "-C" "incremental=/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/issue-80336-invalid-span/issue-80336-invalid-span.inc" "-Z" "incremental-verify-ich" "--error-format" "json" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/issue-80336-invalid-span/a.js" "-Crpath" "-O" "-Cdebuginfo=0" "-Zunstable-options" "-Lnative=/checkout/obj/build/wasm32-unknown-emscripten/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental/issue-80336-invalid-span/auxiliary"
------------------------------------------

------------------------------------------
stderr:
stderr:
------------------------------------------
error[E0658]: use of unstable library feature 'stdsimd'
   |
   |
LL |     let _ = is_x86_feature_detected!("avx2");
   |
   = note: see issue #27731 <https://github.com/rust-lang/rust/issues/27731> for more information
   = note: see issue #27731 <https://github.com/rust-lang/rust/issues/27731> for more information
   = help: add `#![feature(stdsimd)]` to the crate attributes to enable
error: 
error: 
        is_x86_feature_detected can only be used on x86 and x86_64 targets.
        You can prevent it from being used in other architectures by
        guarding it behind a cfg(target_arch) as follows:

            #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] {
                if is_x86_feature_detected(...) { ... }
        
  --> /checkout/src/test/incremental/issue-80336-invalid-span.rs:8:13
   |
   |
LL |     let _ = is_x86_feature_detected!("avx2");
   |
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 2 previous errors
---
test result: FAILED. 125 passed; 1 failed; 1 ignored; 0 measured; 0 filtered out; finished in 17.97s



command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/compiletest" "--compile-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib" "--run-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/wasm32-unknown-emscripten/lib" "--rustc-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "--src-base" "/checkout/src/test/incremental" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/incremental" "--stage-id" "stage2-wasm32-unknown-emscripten" "--suite" "incremental" "--mode" "incremental" "--target" "wasm32-unknown-emscripten" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/checkout/obj/build/x86_64-unknown-linux-gnu/llvm/build/bin/FileCheck" "--nodejs" "/emsdk-portable/node/latest/bin/node" "--host-rustcflags" "-Crpath -O -Cdebuginfo=0 -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--target-rustcflags" "-Crpath -O -Cdebuginfo=0 -Zunstable-options  -Lnative=/checkout/obj/build/wasm32-unknown-emscripten/native/rust-test-helpers" "--docck-python" "/usr/bin/python3" "--lldb-python" "/usr/bin/python3" "--gdb" "/usr/bin/gdb" "--llvm-version" "11.0.0-rust-1.51.0-nightly" "--llvm-components" "aarch64 aarch64asmparser aarch64codegen aarch64desc aarch64disassembler aarch64info aarch64utils aggressiveinstcombine all all-targets analysis arm armasmparser armcodegen armdesc armdisassembler arminfo armutils asmparser asmprinter avr avrasmparser avrcodegen avrdesc avrdisassembler avrinfo binaryformat bitreader bitstreamreader bitwriter cfguard codegen core coroutines coverage debuginfocodeview debuginfodwarf debuginfogsym debuginfomsf debuginfopdb demangle dlltooldriver dwarflinker engine executionengine extensions frontendopenmp fuzzmutate globalisel gtest gtest_main hexagon hexagonasmparser hexagoncodegen hexagondesc hexagondisassembler hexagoninfo instcombine instrumentation interpreter ipo irreader jitlink libdriver lineeditor linker lto mc mca mcdisassembler mcjit mcparser mips mipsasmparser mipscodegen mipsdesc mipsdisassembler mipsinfo mirparser msp430 msp430asmparser msp430codegen msp430desc msp430disassembler msp430info native nativecodegen nvptx nvptxcodegen nvptxdesc nvptxinfo objcarcopts object objectyaml option orcerror orcjit passes powerpc powerpcasmparser powerpccodegen powerpcdesc powerpcdisassembler powerpcinfo profiledata remarks riscv riscvasmparser riscvcodegen riscvdesc riscvdisassembler riscvinfo riscvutils runtimedyld scalaropts selectiondag sparc sparcasmparser sparccodegen sparcdesc sparcdisassembler sparcinfo support symbolize systemz systemzasmparser systemzcodegen systemzdesc systemzdisassembler systemzinfo tablegen target testingsupport textapi transformutils vectorize webassembly webassemblyasmparser webassemblycodegen webassemblydesc webassemblydisassembler webassemblyinfo windowsmanifest x86 x86asmparser x86codegen x86desc x86disassembler x86info xray" "--cc" "" "--cxx" "" "--cflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"


failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test --stage 2 --host= --target wasm32-unknown-emscripten --exclude library/core --exclude library/alloc --exclude library/proc_macro --exclude library/std --exclude library/term --exclude library/test
Build completed unsuccessfully in 0:30:10

[bors]

💔 Test failed - checks-actions

[Aaron1011]

@bors r=wesleywiser

[bors]

📌 Commit 482a67d has been approved by wesleywiser

[bors]

⌛ Testing commit 482a67d with merge 180fdff...

[bors]

☀️ Test successful - checks-actions
Approved by: wesleywiser
Pushing 180fdff to master...