[X86][GlobalIsel] support G_IS_FPCLASS

Author: mahesh-attarde

llvm/lib/Target/X86/GISel/X86LegalizerInfo.cpp

@@ -410,6 +410,9 @@ X86LegalizerInfo::X86LegalizerInfo(const X86Subtarget &STI,
 
   getActionDefinitionsBuilder(G_SEXT_INREG).lower();
 
+  getActionDefinitionsBuilder(G_IS_FPCLASS)
+      .lower();
+
   // fp constants
   getActionDefinitionsBuilder(G_FCONSTANT)
       .legalFor({s32, s64})