TblGen/AsmMatcher: Add support for honoring instruction Requires<[]> attributes as part of the matcher.
 - Currently includes a hack to limit ourselves to "In32BitMode" and "In64BitMode", because we don't have the other infrastructure to properly deal with setting SSE, etc. features on X86.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108677 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCParser/TargetAsmParser.cpp b/lib/MC/MCParser/TargetAsmParser.cpp
index 05760c9..8d43c21 100644
--- a/lib/MC/MCParser/TargetAsmParser.cpp
+++ b/lib/MC/MCParser/TargetAsmParser.cpp
@@ -11,7 +11,7 @@
 using namespace llvm;
 
 TargetAsmParser::TargetAsmParser(const Target &T) 
-  : TheTarget(T)
+  : TheTarget(T), AvailableFeatures(0)
 {
 }