[clang] [Clang][BPF] Add __BPF_FEATURE_GOTOX (PR #165456)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-lld-multistage-test` running on `ppc64le-lld-multistage-test` while building `clang` at step 12 "build-stage2-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/168/builds/16856

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

```
Step 12 (build-stage2-unified-tree) failure: build (failure) (timed out)
...
1321.523 [57/10/6698] Linking CXX executable bin/llvm-c-test
1321.995 [57/9/6699] Linking CXX executable bin/dsymutil
1323.285 [57/8/6700] Linking CXX executable unittests/CodeGen/CGPluginTest/CGPluginTest
1323.843 [57/7/6701] Linking CXX executable bin/llvm-lto
1324.411 [57/6/6702] Linking CXX executable bin/llvm-dwp
1327.157 [57/5/6703] Linking CXX executable unittests/MC/MCTests
1327.871 [57/4/6704] Linking CXX executable bin/lld
1328.061 [57/3/6705] Linking CXX executable bin/opt
1350.109 [57/2/6706] Building CXX object tools/bugpoint-passes/CMakeFiles/BugpointPasses.dir/TestPasses.cpp.o
1352.694 [56/2/6707] Linking CXX shared module lib/BugpointPasses.so
command timed out: 1200 seconds without output running [b'ninja'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=2553.351273

```

</details>

https://github.com/llvm/llvm-project/pull/165456