Adapt -fsanitize=function to SANITIZER_NON_UNIQUE_TYPEINFO

This follows up after b7692bc3 "[UBSan] Fix
isDerivedFromAtOffset on iOS ARM64" fixed the RTTI comparison in
isDerivedFromAtOffset on just one platform and then
a25a2c7c "Always compare C++ typeinfo (based on
libstdc++ implementation)" extended that fix to more platforms.

But there is another RTTI comparison for -fsanitize=function generated in
clang's CodeGenFunction::EmitCall as just a pointer comparison.  For
SANITIZER_NON_UNIQUE_TYPEINFO platforms this needs to be extended to also do
string comparison.  For that, __ubsan_handle_function_type_mismatch[_abort]
takes the two std::type_info pointers as additional parameters now, checks them
internally for potential equivalence, and returns without reporting failure if
they turn out to be equivalent after all.  (NORETURN needed to be dropped from
the _abort variant for that.)  Also these functions depend on ABI-specific RTTI
now, so needed to be moved from plain UBSAN_SOURCES (ubsan_handlers.h/cc) to
UBSAN_CXXABI_SOURCES (ubsan_handlers_cxx.h/cc), but as -fsanitize=function is
only supported in C++ mode that's not a problem.

Differential Revision: https://reviews.llvm.org/D60760

llvm-svn: 359759