This patch implements feature test macros for the CDE extension
according to the upcoming ACLE specification.
The following 2 macros are being added:
- __ARM_FEATURE_CDE - defined as '1' when any coprocessor is configured as a CDE coprocessor
- __ARM_FEATURE_CDE_COPROC - defined as an 8-bit mask, each bit of the mask corresponds to a coprocessor and is set when the corresponding coprocessor is configured as CDE (and cleared otherwise).
The patch also exposes the value of __ARM_FEATURE_CDE_COPROC in the
target-independent method TargetInfo::getARMCDECorpocMask, the method
will be used in follow-up patches implementing semantic checks of CDE
intrinsics (we want to diagnose the cases when CDE intrinsics are used
with coprocessors that are not configured as CDE).