Revert "[OpenCL] An error shall occur if any scalar operand has greater rank...

Revert "[OpenCL] An error shall occur if any scalar operand has greater rank than the type of the vector element"

This reverts commit r303986 as it broke all ARM and AArch64 buildbots...

http://lab.llvm.org:8011/builders/clang-cmake-aarch64-39vma/builds/7007
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-quick/builds/6705
http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15/builds/7509
etc.

llvm-svn: 303996