[clang] [CIR] Materialize AST-derived facts as CIR attributes (PR #215921)

[Bruno Cardoso Lopes via cfe-commits]

================
@@ -1935,6 +1935,52 @@ def CIR_ASTVarDeclAttr : CIR_AST<"VarDecl", "var.decl", [
   ASTVarDeclInterface
 ]>;
 
+//===----------------------------------------------------------------------===//
+// StaticLocalInfoAttr
+//===----------------------------------------------------------------------===//
+
+def CIR_StaticLocalInfoAttr
+    : CIR_Attr<"StaticLocalInfo", "static_local_info",
+               [ASTVarDeclInterface]> {
+  let summary = "AST-free cache of static-local VarDecl facts.";
+  let description = [{
+    Materialized form of the facts `cir::ASTVarDeclInterface` exposes, so
+    that post-CIRGen passes (notably LoweringPrepare) can query them without
+    a live `clang::ASTContext`. Emitted by CIRGen for static-local guarded
+    globals in place of the AST-backed `ASTVarDeclAttr`.
+
+    The TLS and template-specialization kinds are encoded as plain integers
+    matching the underlying `clang::VarDecl::TLSKind` and
+    `clang::TemplateSpecializationKind` enumerators.
+  }];
+
+  let parameters = (ins
+    "bool":$is_local_var_decl,
----------------
bcardosolopes wrote:

If this isn't dependend on the AST anymore it needs to roundtrip parser/printer, which needs tests.

https://github.com/llvm/llvm-project/pull/215921