[clang] Reapply "[HLSL] Rewrite semantics parsing" (#157718) (PR #158044)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-flang-rhel-clang` running on `ppc64le-flang-rhel-test` while building `clang` at step 6 "test-build-unified-tree-check-flang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/157/builds/39616

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-flang) failure: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
...
PASS: Flang :: Driver/fopenmp.f90 (3789 of 3799)
PASS: Flang :: Transforms/stack-arrays.f90 (3790 of 3799)
PASS: Flang :: Driver/riscv-rvv-vector-bits.f90 (3791 of 3799)
PASS: Flang :: Driver/mrecip.f90 (3792 of 3799)
PASS: Flang :: Driver/fveclib.f90 (3793 of 3799)
PASS: Flang :: Driver/use-module.f90 (3794 of 3799)
PASS: Flang :: Driver/options-loongarch.f90 (3795 of 3799)
PASS: Flang :: Driver/mcmodel.f90 (3796 of 3799)
PASS: Flang :: Driver/omp-driver-offload.f90 (3797 of 3799)
PASS: flang-Unit :: Optimizer/./FlangOptimizerTests/145/148 (3798 of 3799)
command timed out: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=2790.964475

```

</details>

https://github.com/llvm/llvm-project/pull/158044