[OpenCL, OpenMP] Fix crash when OpenMP used in OpenCL file

Compiler crashes when omp simd is used in an OpenCL file:

clang -c -fopenmp omp_simd.cl

__kernel void test(global int *data, int size) {
#pragma omp simd
  for (int i = 0; i < size; ++i) {
  }
}

The problem seems to be the check added to verify block pointers have
initializers. An OMPCapturedExprDecl is created to capture ‘size’ but there is
no TypeSourceInfo.

The change just uses getType() directly.

Patch-By: mikerice
Differential Revision: https://reviews.llvm.org/D46667

llvm-svn: 333746