[clang-tidy] Reject invalid enum initializers in C files

C requires that enum values fit into an int.  Scan the macro tokens
present in an initializing expression and reject macros that contain
tokens that have suffixes making them larger than int.

C forbids the comma operator in enum initializing expressions, so
optionally reject comma operator.

Differential Revision: https://reviews.llvm.org/D125622

Fixes #55467