[llvm] Revert "[llvm] simplify and clean-up DemangleConfig.h" (PR #150160)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-expensive-checks-debian` running on `gribozavr4` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/16/builds/23083

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

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: CodeGen/WebAssembly/ref-test-func.ll' FAILED ********************
Exit Code: 2

Command Output (stderr):
--
/b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc < /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/WebAssembly/ref-test-func.ll --mtriple=wasm32-unknown-unknown -mcpu=mvp -mattr=+reference-types | /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/FileCheck --check-prefixes CHECK,CHK32 /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/WebAssembly/ref-test-func.ll # RUN: at line 2
+ /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc --mtriple=wasm32-unknown-unknown -mcpu=mvp -mattr=+reference-types
+ /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/FileCheck --check-prefixes CHECK,CHK32 /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/WebAssembly/ref-test-func.ll
/b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc < /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/WebAssembly/ref-test-func.ll --mtriple=wasm64-unknown-unknown -mcpu=mvp -mattr=+reference-types | /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/FileCheck --check-prefixes CHECK,CHK64 /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/WebAssembly/ref-test-func.ll # RUN: at line 3
+ /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc --mtriple=wasm64-unknown-unknown -mcpu=mvp -mattr=+reference-types
+ /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/FileCheck --check-prefixes CHECK,CHK64 /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/WebAssembly/ref-test-func.ll

# After Post-RA pseudo instruction expansion pass
# Machine code for function test_fpsig_void_void: NoPHIs, TracksLiveness, TiedOpsRewritten
Function Live Ins: $arguments

bb.0.entry:
  liveins: $arguments
  %0:i64 = ARGUMENT_i64 0, implicit $arguments
  %2:i32 = COPY_I32 %0:i64, implicit-def $arguments
  %1:funcref = TABLE_GET_FUNCREF <mcsymbol __indirect_function_table>, %2:i32, implicit-def dead $arguments
  %3:i32 = REF_TEST_FUNCREF i128 2475880060124016476088696832, %1:funcref, implicit-def dead $arguments
  CALL @use, %3:i32, implicit-def dead $arguments, implicit $sp32, implicit $sp64, implicit-def dead $arguments, implicit $sp32, implicit $sp64
  RETURN implicit-def dead $arguments

# End machine code for function test_fpsig_void_void.

*** Bad machine code: Illegal virtual register for instruction ***
- function:    test_fpsig_void_void
- basic block: %bb.0 entry (0xa293320)
- instruction: %2:i32 = COPY_I32 %0:i64, implicit-def $arguments
- operand 1:   %0:i64
Expected a I32 register, but got a I64 register
LLVM ERROR: Found 1 machine code errors.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc --mtriple=wasm64-unknown-unknown -mcpu=mvp -mattr=+reference-types
1.	Running pass 'Function Pass Manager' on module '<stdin>'.
2.	Running pass 'Verify generated machine code' on function '@test_fpsig_void_void'
 #0 0x00000000039890b7 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc+0x39890b7)
 #1 0x0000000003986825 llvm::sys::RunSignalHandlers() (/b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc+0x3986825)
 #2 0x0000000003989dea SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x00007f24ff4e9140 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x13140)
 #4 0x00007f24feffdd61 raise (/lib/x86_64-linux-gnu/libc.so.6+0x38d61)
 #5 0x00007f24fefe7537 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22537)
 #6 0x00000000038f170d llvm::report_fatal_error(llvm::Twine const&, bool) (/b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc+0x38f170d)
 #7 0x0000000002b56b7d (/b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc+0x2b56b7d)
 #8 0x0000000002b57bdb (anonymous namespace)::MachineVerifierLegacyPass::runOnMachineFunction(llvm::MachineFunction&) MachineVerifier.cpp:0:0
 #9 0x0000000002a4d4c3 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc+0x2a4d4c3)
#10 0x0000000002fbf613 llvm::FPPassManager::runOnFunction(llvm::Function&) (/b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc+0x2fbf613)
...

```

</details>

https://github.com/llvm/llvm-project/pull/150160