[X86] Add fxsr feature flag for fxsave/fxrestore instructions.

llvm-svn: 250497
diff --git a/llvm/lib/Target/X86/X86Subtarget.cpp b/llvm/lib/Target/X86/X86Subtarget.cpp
index 428b715..ad593f4 100644
--- a/llvm/lib/Target/X86/X86Subtarget.cpp
+++ b/llvm/lib/Target/X86/X86Subtarget.cpp
@@ -236,6 +236,7 @@
   HasPOPCNT = false;
   HasSSE4A = false;
   HasAES = false;
+  HasFXSR = false;
   HasXSAVE = false;
   HasXSAVEOPT = false;
   HasXSAVEC = false;