[X86] Introduction of FeatureX87.

Add FeatureX87 in X86 backend to be able to define CPUs which doesn't have x87.

Differential Revision: http://reviews.llvm.org/D13979

llvm-svn: 264148
diff --git a/llvm/lib/Target/X86/X86Subtarget.h b/llvm/lib/Target/X86/X86Subtarget.h
index 47977f6..0f40557 100644
--- a/llvm/lib/Target/X86/X86Subtarget.h
+++ b/llvm/lib/Target/X86/X86Subtarget.h
@@ -70,6 +70,9 @@
   /// MMX, 3DNow, 3DNow Athlon, or none supported.
   X863DNowEnum X863DNowLevel;
 
+  /// True if the processor supports X87 instructions.
+  bool HasX87;
+
   /// True if this processor has conditional move instructions
   /// (generally pentium pro+).
   bool HasCMov;
@@ -370,6 +373,7 @@
   PICStyles::Style getPICStyle() const { return PICStyle; }
   void setPICStyle(PICStyles::Style Style)  { PICStyle = Style; }
 
+  bool hasX87() const { return HasX87; }
   bool hasCMov() const { return HasCMov; }
   bool hasSSE1() const { return X86SSELevel >= SSE1; }
   bool hasSSE2() const { return X86SSELevel >= SSE2; }