Add instruction patterns and encodings for the x86 bt instructions.

llvm-svn: 61400
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 398170e..3fda975 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -6513,6 +6513,7 @@
   case X86ISD::CALL:               return "X86ISD::CALL";
   case X86ISD::TAILCALL:           return "X86ISD::TAILCALL";
   case X86ISD::RDTSC_DAG:          return "X86ISD::RDTSC_DAG";
+  case X86ISD::BT:                 return "X86ISD::BT";
   case X86ISD::CMP:                return "X86ISD::CMP";
   case X86ISD::COMI:               return "X86ISD::COMI";
   case X86ISD::UCOMI:              return "X86ISD::UCOMI";