GlobalISel: Don't handle widenScalar for vector G_INSERT

This handling didn't make any sense for vectors.
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 681896e..3471fbe 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -1645,7 +1645,7 @@
 LegalizerHelper::LegalizeResult
 LegalizerHelper::widenScalarInsert(MachineInstr &MI, unsigned TypeIdx,
                                    LLT WideTy) {
-  if (TypeIdx != 0)
+  if (TypeIdx != 0 || WideTy.isVector())
     return UnableToLegalize;
   Observer.changingInstr(MI);
   widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);