GlobalISel: Implement widenScalar for implicit_def

llvm-svn: 350695
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index facbafa..c6e5f3e 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -884,6 +884,12 @@
     Observer.changedInstr(MI);
     return Legalized;
   }
+  case TargetOpcode::G_IMPLICIT_DEF: {
+    Observer.changingInstr(MI);
+    widenScalarDst(MI, WideTy);
+    Observer.changedInstr(MI);
+    return Legalized;
+  }
   case TargetOpcode::G_BRCOND:
     Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 0, TargetOpcode::G_ANYEXT);