AST context's __builtin_va_list type will be set when the PCH file is
loaded. This fixes the crash when CodeGen'ing a va_arg expression
pulled in from a PCH file.
llvm-svn: 69421
lazy PCH deserialization. Propagate that argument wherever it needs to
be. No functionality change, except that I've tightened up a few PCH
tests in preparation.
llvm-svn: 69406
Douglas Gregor