Initialize new subtarget feature variable for generating reciprocal estimate instructions.

This was missed in r221706.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221731 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86Subtarget.cpp

@@ -274,6 +274,7 @@ void X86Subtarget::initializeEnvironment() {
   SlowLEA = false;
   SlowIncDec = false;
   UseSqrtEst = false;
+  UseReciprocalEst = false;
   stackAlignment = 4;
   // FIXME: this is a known good value for Yonah. How about others?
   MaxInlineSizeThreshold = 128;