Newer SDKs don't even provide libstdc++ headers, so it's effectively
never valid to build for libstdc++ unless the user explicitly asks
for it (in which case they will need to provide include paths and more).
This is a re-application of c5ccb78ade which had been reverted in
33171df9cc because it broke the Fuchsia CI bots. The issue was that
the test was XPASSing because it didn't fail anymore when the
CLANG_DEFAULT_CXX_LIB was set to libc++, which seems to be done for
Fuchsia. Instead, the test only fails if CLANG_DEFAULT_CXX_LIB is
set to libstdc++.
As a fly-by fix, also adjust the triple used by various tests to
something that is supported. Those tests were shown to fail on
internal bots.
Differential Revision: https://reviews.llvm.org/D131274
To make them meaningful, it's useful to check "clang". Use
-no-canonical-prefixes to support distributions that symlink %clang to an
executable with a filename not ending in "clang".
A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,
void func();
becomes
void func(void);
This is the sixth batch of tests being updated (there are a significant
number of other tests left to be updated).
Louis Dionne