[clang] [C++20] [Modules] Support generating in-class defined function with try-catch body (PR #129212)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-armv8-quick` running on `linaro-clang-armv8-quick` while building `clang` at step 5 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/154/builds/12796

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

```
Step 5 (ninja check 1) failure: stage 1 checked (failure)
******************** TEST 'Clangd Unit Tests :: ./ClangdTests/49/161' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:/home/tcwg-buildbot/worker/clang-armv8-quick/stage1/tools/clang/tools/extra/clangd/unittests/./ClangdTests-Clangd Unit Tests-2252840-49-161.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=161 GTEST_SHARD_INDEX=49 /home/tcwg-buildbot/worker/clang-armv8-quick/stage1/tools/clang/tools/extra/clangd/unittests/./ClangdTests
--

Note: This is test shard 50 of 161.
[==========] Running 8 tests from 8 test suites.
[----------] Global test environment set-up.
[----------] 1 test from ClangdServerTest
[ RUN      ] ClangdServerTest.ForceReparseCompileCommand
ASTWorker building file /clangd-test/foo.cpp version null with command 
[/clangd-test]
clang -xc /clangd-test/foo.cpp
Driver produced command: cc1 -cc1 -triple armv8a-unknown-linux-gnueabihf -fsyntax-only -disable-free -clear-ast-before-backend -main-file-name foo.cpp -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -target-cpu generic -target-feature +read-tp-tpidruro -target-feature +vfp2 -target-feature +vfp2sp -target-feature +vfp3 -target-feature +vfp3d16 -target-feature +vfp3d16sp -target-feature +vfp3sp -target-feature +fp16 -target-feature +vfp4 -target-feature +vfp4d16 -target-feature +vfp4d16sp -target-feature +vfp4sp -target-feature +fp-armv8 -target-feature +fp-armv8d16 -target-feature +fp-armv8d16sp -target-feature +fp-armv8sp -target-feature -fullfp16 -target-feature +fp64 -target-feature +d32 -target-feature +neon -target-feature +sha2 -target-feature +aes -target-feature -fp16fml -target-abi aapcs-linux -mfloat-abi hard -debugger-tuning=gdb -fdebug-compilation-dir=/clangd-test -fcoverage-compilation-dir=/clangd-test -resource-dir lib/clang/21 -internal-isystem lib/clang/21/include -internal-isystem /usr/local/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -ferror-limit 19 -fno-signed-char -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -no-round-trip-args -faddrsig -x c /clangd-test/foo.cpp
Building first preamble for /clangd-test/foo.cpp version null
Built preamble of size 408800 for file /clangd-test/foo.cpp version null in 6.57 seconds
not idle after addDocument
UNREACHABLE executed at ../llvm/clang-tools-extra/clangd/unittests/SyncAPI.cpp:22!
#0 0x01355fd4 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/tcwg-buildbot/worker/clang-armv8-quick/stage1/tools/clang/tools/extra/clangd/unittests/./ClangdTests+0xaabfd4)
#1 0x013539c4 llvm::sys::RunSignalHandlers() (/home/tcwg-buildbot/worker/clang-armv8-quick/stage1/tools/clang/tools/extra/clangd/unittests/./ClangdTests+0xaa99c4)
#2 0x0135689c SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
#3 0xf759d6f0 __default_rt_sa_restorer ./signal/../sysdeps/unix/sysv/linux/arm/sigrestorer.S:80:0
#4 0xf758db06 ./csu/../sysdeps/unix/sysv/linux/arm/libc-do-syscall.S:47:0
#5 0xf75cd292 __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
#6 0xf759c840 gsignal ./signal/../sysdeps/posix/raise.c:27:6

--
exit: -6
--
shard JSON output does not exist: /home/tcwg-buildbot/worker/clang-armv8-quick/stage1/tools/clang/tools/extra/clangd/unittests/./ClangdTests-Clangd Unit Tests-2252840-49-161.json
********************


```

</details>

https://github.com/llvm/llvm-project/pull/129212