Declare all "fixed" metadata kinds as MetadataKindId

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -1824,3 +1824,55 @@ extern "C" size_t LLVMRustEnzymeGetMaxTypeDepth() {
   return 6; // Default fallback depth
 }
 #endif
+
+// Statically assert that the fixed metadata kind IDs declared in
+// `metadata_kind.rs` match the ones actually used by LLVM.
+#define FIXED_MD_KIND(VARIANT, VALUE)                                          \
+  static_assert(::llvm::LLVMContext::VARIANT == VALUE);
+// Must be kept in sync with the corresponding list in `metadata_kind.rs`.
+FIXED_MD_KIND(MD_dbg, 0)
+FIXED_MD_KIND(MD_tbaa, 1)
+FIXED_MD_KIND(MD_prof, 2)
+FIXED_MD_KIND(MD_fpmath, 3)
+FIXED_MD_KIND(MD_range, 4)
+FIXED_MD_KIND(MD_tbaa_struct, 5)
+FIXED_MD_KIND(MD_invariant_load, 6)
+FIXED_MD_KIND(MD_alias_scope, 7)
+FIXED_MD_KIND(MD_noalias, 8)
+FIXED_MD_KIND(MD_nontemporal, 9)
+FIXED_MD_KIND(MD_mem_parallel_loop_access, 10)
+FIXED_MD_KIND(MD_nonnull, 11)
+FIXED_MD_KIND(MD_dereferenceable, 12)
+FIXED_MD_KIND(MD_dereferenceable_or_null, 13)
+FIXED_MD_KIND(MD_make_implicit, 14)
+FIXED_MD_KIND(MD_unpredictable, 15)
+FIXED_MD_KIND(MD_invariant_group, 16)
+FIXED_MD_KIND(MD_align, 17)
+FIXED_MD_KIND(MD_loop, 18)
+FIXED_MD_KIND(MD_type, 19)
+FIXED_MD_KIND(MD_section_prefix, 20)
+FIXED_MD_KIND(MD_absolute_symbol, 21)
+FIXED_MD_KIND(MD_associated, 22)
+FIXED_MD_KIND(MD_callees, 23)
+FIXED_MD_KIND(MD_irr_loop, 24)
+FIXED_MD_KIND(MD_access_group, 25)
+FIXED_MD_KIND(MD_callback, 26)
+FIXED_MD_KIND(MD_preserve_access_index, 27)
+FIXED_MD_KIND(MD_vcall_visibility, 28)
+FIXED_MD_KIND(MD_noundef, 29)
+FIXED_MD_KIND(MD_annotation, 30)
+FIXED_MD_KIND(MD_nosanitize, 31)
+FIXED_MD_KIND(MD_func_sanitize, 32)
+FIXED_MD_KIND(MD_exclude, 33)
+FIXED_MD_KIND(MD_memprof, 34)
+FIXED_MD_KIND(MD_callsite, 35)
+FIXED_MD_KIND(MD_kcfi_type, 36)
+FIXED_MD_KIND(MD_pcsections, 37)
+FIXED_MD_KIND(MD_DIAssignID, 38)
+FIXED_MD_KIND(MD_coro_outside_frame, 39)
+FIXED_MD_KIND(MD_mmra, 40)
+FIXED_MD_KIND(MD_noalias_addrspace, 41)
+// If some fixed metadata kinds are not present and consistent in all supported
+// LLVM versions, it's fine to omit them from this list; in that case Rust-side
+// code cannot declare them as fixed IDs and must look them up by name instead.
+#undef FIXED_MD_KIND