[clang] [Clang] Eagerly instantiate used constexpr function upon definition. (PR #73463)

[Richard Smith via cfe-commits]

================
@@ -4836,6 +4837,16 @@ ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
   assert(SemaRef.PendingLocalImplicitInstantiations.empty() &&
          "There are local ones at end of translation unit!");
 
+  // Build a record containing all of pending instantiations of constexpr
----------------
zygoloid wrote:

```suggestion
  // Build a record containing all pending instantiations of constexpr
```

https://github.com/llvm/llvm-project/pull/73463