Stub out codegen for __builtin_constant_p. Remove any implicit cast exprs in the call to __builtin___CFStringMakeConstantString.

llvm-svn: 43592

llvm-svn: 43429

llvm-svn: 42939

llvm-svn: 41907

to their corresponding library routines (e.g. isinf).  This allows us to handle
all the stuff in macos math.h, and other stuff as it's added to *Builtins.def.

llvm-svn: 41634

llvm-svn: 41633

llvm-svn: 41419

llvm-svn: 41206

llvm-svn: 41188