Use std::bitset for SubtargetFeatures.

Previously, subtarget features were a bitfield with the underlying type being uint64_t. 
Since several targets (X86 and ARM, in particular) have hit or were very close to hitting this bound, switching the features to use a bitset.
No functional change.

The first several times this was committed (e.g. r229831, r233055), it caused several buildbot failures.
Apparently the reason for most failures was both clang and gcc's inability to deal with large numbers (> 10K) of bitset constructor calls in tablegen-generated initializers of instruction info tables. 
This should now be fixed.

llvm-svn: 238192

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/MC/MCInstrDesc.cpp b/llvm/lib/MC/MCInstrDesc.cpp
index 0f942cd3a74..decc2d84b25 100644
--- a/llvm/lib/MC/MCInstrDesc.cpp
+++ b/llvm/lib/MC/MCInstrDesc.cpp
@@ -23,7 +23,7 @@ bool MCInstrDesc::getDeprecatedInfo(MCInst &MI, MCSubtargetInfo &STI,
                                     std::string &Info) const {
   if (ComplexDeprecationInfo)
     return ComplexDeprecationInfo(MI, STI, Info);
-  if ((DeprecatedFeatureMask & STI.getFeatureBits()) != 0) {
+  if (DeprecatedFeature != -1 && STI.getFeatureBits()[DeprecatedFeature]) {
     // FIXME: it would be nice to include the subtarget feature here.
     Info = "deprecated";
     return true;