Fix the literals parsers not following coercions.

Closes #1858.

spicy/toolchain/src/compiler/codegen/parsers/literals.cc

@@ -138,6 +138,8 @@ struct Visitor : public visitor::PreOrder {
         hilti::util::cannotBeReached();
     }
 
+    void operator()(hilti::ctor::Coerced* n) final { dispatch(n->coercedCtor()); }
+
     void operator()(hilti::ctor::RegExp* n) final {
         auto re = hilti::ID(fmt("__re_%" PRId64, lp->production->tokenID()));
 
@@ -249,7 +251,7 @@ struct Visitor : public visitor::PreOrder {
         hilti::util::cannotBeReached();
     }
 
-    void operator()(hilti::expression::Ctor* n) final { result = lp->buildParser(n->ctor()); }
+    void operator()(hilti::expression::Ctor* n) final { dispatch(n->ctor()); }
 
     Expression* parseInteger(UnqualifiedType* type, Expression* expected, const Meta& meta) {
         auto offset = [this](Expression* view) { return builder()->memberCall(view, "offset"); };
@@ -419,7 +421,8 @@ Expression* ParserBuilder::parseLiteral(const Production& p, Expression* dst) {
     if ( auto e = LiteralParser(this, &p, dst).buildParser(p.expression()) )
         return e;
 
-    hilti::logger().internalError(fmt("codegen: literal parser did not return expression for '%s'", *p.expression()));
+    hilti::logger().internalError(fmt("codegen: literal parser did not return expression for '%s' (%s)",
+                                      *p.expression(), p.expression()->typename_()));
 }
 
 void ParserBuilder::skipLiteral(const Production& p) {

tests/spicy/types/integer/parse-coerced-ctor.spicy

@@ -0,0 +1,11 @@
+# @TEST-EXEC: printf a | spicy-driver -d %INPUT >output
+#
+# @TEST-DOC: Checks that the literals parsers follows coercions; regression test for #1858
+
+module foo;
+
+const a: uint8 = 97; # will be coerced
+
+public type X = unit {
+   : a;
+};