[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-key-instructions` running on `sie-linux-worker5` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/208/builds/416

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
11.151 [4101/10/2460] Building CXX object lib/Target/CMakeFiles/LLVMTarget.dir/TargetMachineC.cpp.o
12.827 [4100/10/2461] Building AArch64GenExegesis.inc...
12.887 [4099/10/2462] Building CXX object lib/Object/CMakeFiles/LLVMObject.dir/IRSymtab.cpp.o
14.074 [4098/10/2463] Building AArch64GenAsmMatcher.inc...
14.601 [4097/10/2464] Building AArch64GenFastISel.inc...
14.884 [4096/10/2465] Building AArch64GenAsmWriter.inc...
14.958 [4095/10/2466] Building AArch64GenAsmWriter1.inc...
15.518 [4094/10/2467] Building AArch64GenCallingConv.inc...
16.027 [4093/10/2468] Building AArch64GenGlobalISel.inc...
16.739 [4092/10/2469] Building AArch64GenDisassemblerTables.inc...
FAILED: lib/Target/AArch64/AArch64GenDisassemblerTables.inc /home/buildbot/buildbot-root/llvm-ki/build/lib/Target/AArch64/AArch64GenDisassemblerTables.inc 
cd /home/buildbot/buildbot-root/llvm-ki/build && /home/buildbot/buildbot-root/llvm-ki/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/buildbot/buildbot-root/llvm-ki/llvm-project/llvm/lib/Target/AArch64 -I/home/buildbot/buildbot-root/llvm-ki/build/include -I/home/buildbot/buildbot-root/llvm-ki/llvm-project/llvm/include -I /home/buildbot/buildbot-root/llvm-ki/llvm-project/llvm/lib/Target /home/buildbot/buildbot-root/llvm-ki/llvm-project/llvm/lib/Target/AArch64/AArch64.td --write-if-changed -o lib/Target/AArch64/AArch64GenDisassemblerTables.inc -d lib/Target/AArch64/AArch64GenDisassemblerTables.inc.d
llvm-tblgen: /home/buildbot/buildbot-root/llvm-ki/llvm-project/llvm/utils/TableGen/DecoderEmitter.cpp:150: void {anonymous}::DecoderTable::patchNumToSkip(size_t, uint32_t): Assertion `DestIdx > FixupIdx + NumToSkipSizeInBytes && "Expecting a forward jump in the decoding table"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /home/buildbot/buildbot-root/llvm-ki/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/buildbot/buildbot-root/llvm-ki/llvm-project/llvm/lib/Target/AArch64 -I/home/buildbot/buildbot-root/llvm-ki/build/include -I/home/buildbot/buildbot-root/llvm-ki/llvm-project/llvm/include -I /home/buildbot/buildbot-root/llvm-ki/llvm-project/llvm/lib/Target /home/buildbot/buildbot-root/llvm-ki/llvm-project/llvm/lib/Target/AArch64/AArch64.td --write-if-changed -o lib/Target/AArch64/AArch64GenDisassemblerTables.inc -d lib/Target/AArch64/AArch64GenDisassemblerTables.inc.d
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  llvm-tblgen 0x00005557b87454a0
1  llvm-tblgen 0x00005557b8742a7f
2  llvm-tblgen 0x00005557b8742bca
3  libc.so.6   0x00007989bb532520
4  libc.so.6   0x00007989bb5869fc pthread_kill + 300
5  libc.so.6   0x00007989bb532476 raise + 22
6  libc.so.6   0x00007989bb5187f3 abort + 211
7  libc.so.6   0x00007989bb51871b
8  libc.so.6   0x00007989bb529e96
9  llvm-tblgen 0x00005557b85b9cde
10 llvm-tblgen 0x00005557b85c5571
11 llvm-tblgen 0x00005557b85c5153
12 llvm-tblgen 0x00005557b85c69e9
13 llvm-tblgen 0x00005557b85db346
14 llvm-tblgen 0x00005557b87831af
15 llvm-tblgen 0x00005557b875095d
16 llvm-tblgen 0x00005557b8427968
17 libc.so.6   0x00007989bb519d90
18 libc.so.6   0x00007989bb519e40 __libc_start_main + 128
19 llvm-tblgen 0x00005557b83f1875
Aborted (core dumped)
16.866 [4092/9/2470] Building AArch64GenMCCodeEmitter.inc...
16.957 [4092/8/2471] Building AArch64GenMCPseudoLowering.inc...
17.719 [4092/7/2472] Building AArch64GenO0PreLegalizeGICombiner.inc...
19.012 [4092/6/2473] Building CXX object lib/MC/MCParser/CMakeFiles/LLVMMCParser.dir/AsmParser.cpp.o
19.590 [4092/5/2474] Building AArch64GenDAGISel.inc...
22.329 [4092/4/2475] Building AArch64GenInstrInfo.inc...
22.928 [4092/3/2476] Building CXX object lib/CodeGen/AsmPrinter/CMakeFiles/LLVMAsmPrinter.dir/AsmPrinter.cpp.o
23.537 [4092/2/2477] Building AMDGPUGenRegBankGICombiner.inc...
25.275 [4092/1/2478] Building CXX object lib/LTO/CMakeFiles/LLVMLTO.dir/LTO.cpp.o
ninja: build stopped: subcommand failed.

```

</details>

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