Merge upstream stable

CHANGELOG.md

@@ -1,9 +1,11 @@
 # LDC master
 
 #### Big news
-- Frontend, druntime and Phobos are at version [2.108.0](https://dlang.org/changelog/2.108.0.html). (#4591)
+- Frontend, druntime and Phobos are at version [2.108.0](https://dlang.org/changelog/2.108.0.html). (#4591, #4615)
+- Preliminary support for LLVM 18. (#4599, #4605, #4607)
 
 #### Platform support
+- Supports LLVM 11 - 18.
 
 #### Bug fixes
 

packaging/dlang-tools_version

@@ -1 +1 @@
-v2.107.1
+v2.108.0

packaging/dub_version

@@ -1 +1 @@
-v1.36.0
+v1.37.0

runtime/druntime/src/core/internal/array/duplication.d

@@ -21,9 +21,9 @@ U[] _dup(T, U)(scope T[] a) pure nothrow @trusted if (__traits(isPOD, T))
     {
         import core.stdc.string : memcpy;
         import core.internal.array.construction: _d_newarrayUPureNothrow;
-        auto arr = _d_newarrayUPureNothrow!T(a.length, is(T == shared));
+        auto arr = _d_newarrayUPureNothrow!U(a.length, is(U == shared));
         memcpy(cast(void*) arr.ptr, cast(const(void)*) a.ptr, T.sizeof * a.length);
-        return *cast(U[]*) &arr;
+        return arr;
     }
 }
 
@@ -358,3 +358,13 @@ U[] _dup(T, U)(T[] a) if (!__traits(isPOD, T))
     static assert(test!Copy());
     assert(test!Copy());
 }
+
+// https://issues.dlang.org/show_bug.cgi?id=24453
+@safe unittest
+{
+    static inout(char)[] foo(ref scope return inout(char)[] s)
+    {
+        auto bla = s.idup;
+        return s;
+    }
+}