New testcase, checking to see we can turn this code:

void test(vector float *F, float f) {
  vector float G = *F + *F;
  *((float*)&G) = f;
  *F = G + G;
}

void test2(vector float *F, float f) {
  vector float G = *F + *F;
  ((float*)&G)[2] = f;
  *F = G + G;
}

void test3(vector float *F, float *f) {
  vector float G = *F + *F;
  *f = ((float*)&G)[2];
}

void test4(vector float *F, float *f) {
  vector float G = *F + *F;
  *f = *((float*)&G);
}

into insert/extract element operations with no memory traffic.

llvm-svn: 27709