[X86][GlobalIsel] Support G_IS_FPCLASS (llvm#162232)

Some of dependency opcodes for G_IS_FPCLASS are now supported. This
patch adds lowering for G_IS_FPCLASS.
Test is updated for GISEL Run separately [Test
PR] llvm#160741.

Author: mahesh-attarde

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

@@ -414,6 +414,8 @@ X86LegalizerInfo::X86LegalizerInfo(const X86Subtarget &STI,
 
   getActionDefinitionsBuilder(G_SEXT_INREG).lower();
 
+  getActionDefinitionsBuilder(G_IS_FPCLASS).lower();
+
   // fp constants
   getActionDefinitionsBuilder(G_FCONSTANT)
       .legalFor({s32, s64})