libc: Add GCC fno-builtin-malloc flag to common stdlib compilation

This prevents the compiler from optimizing calloc into an
infinite recursive call.

For example a call to malloc + memset zero at GCC -O2 will be
replaced by a call to calloc. This causes infinite recursion
if the function being implemented *is* calloc.

fno-builtin-malloc forces the compiler to avoid this optimization.

Signed-off-by: Grant Ramsay <gramsay@enphaseenergy.com>
1 file changed