Auto merge of #133990 - Walnut356:static_const, r=workingjubilee

[Debuginfo] Force enum `DISCR_*` to `static const u64` to allow for inspection via LLDB

see [here](486614878) for more info.

This change mainly helps `*-msvc` debugged with LLDB. Currently, LLDB cannot inspect `static` struct fields, so the intended visualization for enums is only borderline functional, and niche enums with ranges of discriminant cannot be determined at all .

LLDB *can* inspect `static const` values (though for whatever reason, non-enum/non-u64 consts don't work).

This change adds the `LLVMRustDIBuilderCreateQualifiedType` to the rust FFI layer to wrap the discr type with a `const` modifier, as well as forcing all generated integer enum `DISCR_*` values to be u64's. Those values will only ever be used by debugger visualizers anyway, so it shouldn't be a huge deal, but I left a fixme comment for it just in case.. The `tag` also still properly reflects the discriminant type, so no information is lost.

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -1217,6 +1217,13 @@ extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateStaticMemberType(
       unwrap<llvm::ConstantInt>(val), llvm::dwarf::DW_TAG_member, AlignInBits));
 }
 
+extern "C" LLVMMetadataRef
+LLVMRustDIBuilderCreateQualifiedType(LLVMDIBuilderRef Builder, unsigned Tag,
+                                     LLVMMetadataRef Type) {
+  return wrap(
+      unwrap(Builder)->createQualifiedType(Tag, unwrapDI<DIType>(Type)));
+}
+
 extern "C" LLVMMetadataRef
 LLVMRustDIBuilderCreateLexicalBlock(LLVMRustDIBuilderRef Builder,
                                     LLVMMetadataRef Scope, LLVMMetadataRef File,