Use -fno-builtin for libc and libm.

clang was getting in the way of a strftime(3) optimization, and smaller
hammers weren't working, and this seems like the right choice for libc
anyway? If we have code that can usefully be optimized, we should do it
in the source. In general, though, no libc/libm author should be
ignorant of memset(3) or memcpy(3), and would have used it themselves if
it made sense. (And the compiler isn't using profiling data or anything;
it's just always assuming it should use the functions, and doesn't
consider whether the cost of the calls can be amortized or not.)

Test: treehugger
Change-Id: Ia7e22623e47bfbfcfe46c1af0d95ef7e8669c0f6

0 files changed, 0 insertions, 0 deletions