This patch fixes builtins' CMakeLists.txt and their VFP tests to check the standard macro defined in the ACLE for VFP support. It also enables the tests to be built and run for single-precision-only targets while builtins were built with double-precision support.
Following the ACLE is definitely preferable. One thing to verify is if gcc does support this correctly as well. IIRC, it does support __ARM_FP properly and this should be safe, but please do verify that.