Fix floating point vector frem lowering.
The frem operation takes two arguments.
Pass both Src0 and Src1 to __frem_v4f32.

BUG=none
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/387153002
diff --git a/src/IceTargetLoweringX8632.cpp b/src/IceTargetLoweringX8632.cpp
index bf11573..e459e2c 100644
--- a/src/IceTargetLoweringX8632.cpp
+++ b/src/IceTargetLoweringX8632.cpp
@@ -1182,9 +1182,10 @@
       _movp(Dest, T);
     } break;
     case InstArithmetic::Frem: {
-      const SizeT MaxSrcs = 1;
+      const SizeT MaxSrcs = 2;
       InstCall *Call = makeHelperCall("__frem_v4f32", Dest, MaxSrcs);
       Call->addArg(Src0);
+      Call->addArg(Src1);
       lowerCall(Call);
     } break;
     }