This is the second fix related to VZEXT_MOVL node.

This is the second fix related to VZEXT_MOVL node.
The failure that I see in the current version is:

LLVM ERROR: Cannot select: 0x18b8f70: v4i64 = X86ISD::VZEXT_MOVL 0x18beee0 [ID=14]
  0x18beee0: v4i64 = insert_subvector 0x18b8c70, 0x18b9170, 0x18b9570 [ID=13]
    0x18b8c70: v4i64 = insert_subvector 0x18b9870, 0x18bf4e0, 0x18b9970 [ID=12]
      0x18b9870: v4i64 = undef [ID=4]
      0x18bf4e0: v2i64 = bitcast 0x18bf3e0 [ID=10]
        0x18bf3e0: v4i32 = BUILD_VECTOR 0x18b9770, 0x18b9770, 0x18b9770, 0x18b9770 [ID=8]
          0x18b9770: i32 = TargetConstant<0> [ID=6]
          0x18b9770: i32 = TargetConstant<0> [ID=6]
          0x18b9770: i32 = TargetConstant<0> [ID=6]
          0x18b9770: i32 = TargetConstant<0> [ID=6]
      0x18b9970: i32 = Constant<0> [ID=3]
    0x18b9170: v2i64 = undef [ORD=1] [ID=1]
    0x18b9570: i32 = Constant<2> [ID=5]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146975 91177308-0d34-0410-b5e6-96231b3b80d8