llvm-project

f3761a4b - [C++20][Modules] Allow using stdarg.h with header units (#100739)

[C++20][Modules] Allow using stdarg.h with header units (#100739) Summary: Macro like `va_start`/`va_end` marked as builtin functions that makes these identifiers special and it results in redefinition of the identifiers as builtins and it hides macro definitions during preloading C++ modules. In case of modules Clang ignores special identifiers but `PP.getCurrentModule()` was not set. This diff fixes IsModule detection logic for this particular case. Test Plan: check-clang --------- Co-authored-by: Chuanqi Xu <yedeng.yd@linux.alibaba.com>