[X86] Make an assert in LowerSCALAR_TO_VECTOR stricter to make it clear what types are allowed here. NFC

Make it clear that only integer type with i32 or smaller elements shoudl get to this part of the code.

llvm-svn: 363629

Author: topperc

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -17175,7 +17175,8 @@ static SDValue LowerSCALAR_TO_VECTOR(SDValue Op, const X86Subtarget &Subtarget,
     // Insert the 128-bit vector.
     return insert128BitVector(DAG.getUNDEF(OpVT), Op, 0, DAG, dl);
   }
-  assert(OpVT.is128BitVector() && "Expected an SSE type!");
+  assert(OpVT.is128BitVector() && OpVT.isInteger() && OpVT != MVT::v2i64 &&
+         "Expected an SSE type!");
 
   // Pass through a v4i32 SCALAR_TO_VECTOR as that's what we use in tblgen.
   if (OpVT == MVT::v4i32)