[CIR] Upstream support for goto handling

### Overview
Upstream support for handling goto statements in ClangIR.

This will also require upstreaming of the GotoSolver transform from the ClangIR incubator.

### Suggested minimal test case
```
void g0(int a) {
  int b = a;
  goto end;
  b = b + 1;
end:
  b = b + 2;
}
```

### Existing incubator tests
clang/test/CIR/CodeGen/goto.cpp