K 10
svn:author
V 3
dim
K 8
svn:date
V 27
2021-12-25T12:08:38.777714Z
K 7
svn:log
V 720
Add kludges for old gcc builds of compiler-rt builtins

Only use the __libgcc_cmp_return__ mode attribute for gcc > 4.2, as it
was only introduced in gcc 4.3.0.

Don't use __has_include() for old gcc (actually cpp), as this results in
'missing binary operator before token "("' errors. Also add a forced
<stdbool.h> include, since old gcc refuses to recognize the 'bool' type
in freestanding mode.

Use the inline __builtin_sadd_overflow() implementation (originally
provided for MSVC) for gcc < 5.0, as it was only introduced in gcc 5.0.

NOTE: since the llvm project requires at least gcc >= 5.1, these kludges
should not be upstreamed.

Git Hash:   ed0550041614dbb5c2d1d231c7550e1af69f459e
Git Author: dim@FreeBSD.org
END