[llvm] [HLSL] Leave out entryname from string table for PSV versions < 3 (PR #191528)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

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

Full details are available at: https://lab.llvm.org/buildbot/#/builders/95/builds/20717

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

```
Step 6 (test-build-unified-tree-check-all) failure: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
...
PASS: UBSan-MemorySanitizer-powerpc64le :: TestCases/ImplicitConversion/signed-integer-truncation-ignorelist.c (109942 of 109952)
PASS: Clang :: Preprocessor/init.c (109943 of 109952)
PASS: LLVM :: Transforms/LoopUnroll/branch-weights-freq/unroll-complete.ll (109944 of 109952)
PASS: lit :: shtest-define.py (109945 of 109952)
PASS: LLVM :: tools/llvm-readobj/ELF/mips-abiflags.test (109946 of 109952)
PASS: LLVM :: CodeGen/X86/cpus-intel.ll (109947 of 109952)
PASS: LLVM :: CodeGen/AMDGPU/directive-amdgcn-target.ll (109948 of 109952)
PASS: LLVM :: CodeGen/RISCV/attributes.ll (109949 of 109952)
PASS: Clang :: Driver/linux-ld.c (109950 of 109952)
PASS: Clang :: OpenMP/target_update_codegen.cpp (109951 of 109952)
command timed out: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=14698.808070

```

</details>

https://github.com/llvm/llvm-project/pull/191528