[llvm] [LLVM][TableGen] Parameterize NumToSkip in DecoderEmitter (PR #135882)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-sie-win` running on `sie-win-worker` while building `llvm` at step 7 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/46/builds/15301

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

```
Step 7 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: TableGen/FixedLenDecoderEmitter/conflict.td' FAILED ********************
Exit Code: 2147483651

Command Output (stdout):
--
# RUN: at line 1
z:\b\llvm-clang-x86_64-sie-win\build\bin\llvm-tblgen.exe -gen-disassembler -I Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\TableGen\FixedLenDecoderEmitter/../../../include Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\TableGen\FixedLenDecoderEmitter\conflict.td -o - 2>Z:\b\llvm-clang-x86_64-sie-win\build\test\TableGen\FixedLenDecoderEmitter\Output\conflict.td.tmp
# executed command: 'z:\b\llvm-clang-x86_64-sie-win\build\bin\llvm-tblgen.exe' -gen-disassembler -I 'Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\TableGen\FixedLenDecoderEmitter/../../../include' 'Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\test\TableGen\FixedLenDecoderEmitter\conflict.td' -o -
# .---redirected output from 'Z:\b\llvm-clang-x86_64-sie-win\build\test\TableGen\FixedLenDecoderEmitter\Output\conflict.td.tmp'
# | Decoding Conflict:
# | 		00000000000000000000000000000000
# | 		................................
# | 	A 00000000000000000000000000000000
# | 	B 00000000000000000000000000000000
# | Assertion failed: DestIdx > FixupIdx + NumToSkipSizeInBytes && "Expecting a forward jump in the decoding table", file Z:\b\llvm-clang-x86_64-sie-win\llvm-project\llvm\utils\TableGen\DecoderEmitter.cpp, line 151
# | PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
# | Stack dump:
# | 0.	Program arguments: z:\\b\\llvm-clang-x86_64-sie-win\\build\\bin\\llvm-tblgen.exe -gen-disassembler -I Z:\\b\\llvm-clang-x86_64-sie-win\\llvm-project\\llvm\\test\\TableGen\\FixedLenDecoderEmitter/../../../include Z:\\b\\llvm-clang-x86_64-sie-win\\llvm-project\\llvm\\test\\TableGen\\FixedLenDecoderEmitter\\conflict.td -o -
# | Exception Code: 0x80000003
# |  #0 0x00007ff7d29e4e65 (z:\b\llvm-clang-x86_64-sie-win\build\bin\llvm-tblgen.exe+0x2e4e65)
# |  #1 0x00007ff8bb44d88d (C:\Windows\System32\ucrtbase.dll+0x6d88d)
# |  #2 0x0000
# | ...
# `---data was truncated--------
# note: command had no output on stdout or stderr
# error: command failed with exit status: 0x80000003

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/135882