[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-darwin` running on `doug-worker-3` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/23/builds/9443

<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 :: TableGen/FixedLenDecoderEmitter/conflict.td' FAILED ********************
Exit Code: 134

Command Output (stderr):
--
/Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/llvm-tblgen -gen-disassembler -I /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/llvm/test/TableGen/FixedLenDecoderEmitter/../../../include /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/llvm/test/TableGen/FixedLenDecoderEmitter/conflict.td -o - 2>/Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/test/TableGen/FixedLenDecoderEmitter/Output/conflict.td.tmp # RUN: at line 1
+ /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/llvm-tblgen -gen-disassembler -I /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/llvm/test/TableGen/FixedLenDecoderEmitter/../../../include /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/llvm/test/TableGen/FixedLenDecoderEmitter/conflict.td -o -
/Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/test/TableGen/FixedLenDecoderEmitter/Output/conflict.td.script: line 2: 66815 Abort trap: 6           /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/llvm-tblgen -gen-disassembler -I /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/llvm/test/TableGen/FixedLenDecoderEmitter/../../../include /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/llvm/test/TableGen/FixedLenDecoderEmitter/conflict.td -o - 2> /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/test/TableGen/FixedLenDecoderEmitter/Output/conflict.td.tmp

--

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


```

</details>

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