[llvm] [CodeGen] Use TargetLowering for TypeInfo of PointerTy (PR #93469)

[Pete Steinfeld via llvm-commits]

psteinfeld wrote:

@jplehr, here's a small test case the reproduces the original crash.  I've tested the changes in this merge request, and they seem to fix it.

```
// clang -O2 -c -march=skylake-avx512 bug.c

typedef struct {
  const char *p;
  union {
    int i;
  } val;
} xcFooVal;

typedef struct {
  int n_vals;
  xcFooVal *vals;
} xcFooData;

typedef struct {
  xcFooData *bar;
  xcFooData *total_XX;
} YY_data;

extern xcFooData *XXbar, *XXbar1;

void func(const char *where) {
  YY_data data;
  data.bar = XXbar;
  data.total_XX = XXbar1;
  int i;
  for (i = 0; i < data.total_XX->n_vals; i++) {
    data.total_XX->vals[i].p = data.bar->vals[i].p;
  }
}
```

https://github.com/llvm/llvm-project/pull/93469