Fix assertion when passing function into inline asm's input operand

This seem to be a regression caused by this change:
https://reviews.llvm.org/D60943.
Since we delayed report the error, we would run into some invalid
state in clang and llvm.

Without this fix, clang would assert when passing function into
inline asm's input operand.

Differential Revision: https://reviews.llvm.org/D107941