[llvm] Allow this test to pass when the source is on a read-only filesystem (PR #134179)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `lldb-aarch64-ubuntu` running on `linaro-lldb-aarch64-ubuntu` while building `llvm` at step 6 "test".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/59/builds/15360

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

```
Step 6 (test) failure: build (failure)
...
PASS: lldb-api :: tools/lldb-server/thread-name/TestGdbRemoteThreadName.py (1226 of 2115)
PASS: lldb-api :: tools/lldb-server/libraries-svr4/TestGdbRemoteLibrariesSvr4Support.py (1227 of 2115)
UNSUPPORTED: lldb-api :: tools/lldb-server/vCont-threads/TestSignal.py (1228 of 2115)
PASS: lldb-api :: types/TestDoubleTypes.py (1229 of 2115)
PASS: lldb-api :: types/TestCharType.py (1230 of 2115)
PASS: lldb-api :: tools/lldb-server/qSupported/TestGdbRemote_qSupported.py (1231 of 2115)
PASS: lldb-api :: types/TestCharTypeExpr.py (1232 of 2115)
PASS: lldb-api :: types/TestDoubleTypesExpr.py (1233 of 2115)
PASS: lldb-api :: types/TestFloatTypes.py (1234 of 2115)
PASS: lldb-api :: tools/lldb-server/TestGdbRemote_vCont.py (1235 of 2115)
FAIL: lldb-api :: types/TestFloatTypesExpr.py (1236 of 2115)
******************** TEST 'lldb-api :: types/TestFloatTypesExpr.py' FAILED ********************
Script:
--
/usr/bin/python3.10 /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/test/API/dotest.py -u CXXFLAGS -u CFLAGS --env LLVM_LIBS_DIR=/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./lib --env LLVM_INCLUDE_DIR=/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/include --env LLVM_TOOLS_DIR=/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./bin --arch aarch64 --build-dir /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lldb-test-build.noindex --lldb-module-cache-dir /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lldb-test-build.noindex/module-cache-lldb/lldb-api --clang-module-cache-dir /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lldb-test-build.noindex/module-cache-clang/lldb-api --executable /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./bin/lldb --compiler /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./bin/clang --dsymutil /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./bin/dsymutil --make /usr/bin/gmake --llvm-tools-dir /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./bin --lldb-obj-root /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/tools/lldb --lldb-libs-dir /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./lib /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/test/API/types -p TestFloatTypesExpr.py
--
Exit Code: -11

Command Output (stdout):
--
lldb version 21.0.0git (https://github.com/llvm/llvm-project.git revision f68a5185d0959929bd0b0249a8128d0720315dab)
  clang revision f68a5185d0959929bd0b0249a8128d0720315dab
  llvm revision f68a5185d0959929bd0b0249a8128d0720315dab
Skipping the following test categories: ['libc++', 'dsym', 'gmodules', 'debugserver', 'objc']

--
Command Output (stderr):
--
UNSUPPORTED: LLDB (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/bin/clang-aarch64) :: test_float_type_dsym (TestFloatTypesExpr.FloatTypesExprTestCase) (test case does not fall in any category of interest for this run) 
PASS: LLDB (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/bin/clang-aarch64) :: test_float_type_dwarf (TestFloatTypesExpr.FloatTypesExprTestCase)
PASS: LLDB (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/bin/clang-aarch64) :: test_float_type_dwo (TestFloatTypesExpr.FloatTypesExprTestCase)
UNSUPPORTED: LLDB (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/bin/clang-aarch64) :: test_float_type_from_block_dsym (TestFloatTypesExpr.FloatTypesExprTestCase) (test case does not fall in any category of interest for this run) 
UNSUPPORTED: LLDB (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/bin/clang-aarch64) :: test_float_type_from_block_dwarf (TestFloatTypesExpr.FloatTypesExprTestCase) (requires one of macosx, darwin, ios, tvos, watchos, bridgeos, iphonesimulator, watchsimulator, appletvsimulator) 
UNSUPPORTED: LLDB (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/bin/clang-aarch64) :: test_float_type_from_block_dwo (TestFloatTypesExpr.FloatTypesExprTestCase) (requires one of macosx, darwin, ios, tvos, watchos, bridgeos, iphonesimulator, watchsimulator, appletvsimulator) 
----------------------------------------------------------------------
Ran 6 tests in 1.020s

OK (skipped=4)

--

********************
PASS: lldb-api :: tools/lldb-server/vCont-threads/TestPartialResume.py (1237 of 2115)
PASS: lldb-api :: types/TestIntegerType.py (1238 of 2115)
PASS: lldb-api :: types/TestIntegerTypeExpr.py (1239 of 2115)
PASS: lldb-api :: types/TestRecursiveTypes.py (1240 of 2115)
UNSUPPORTED: lldb-shell :: Breakpoint/case-insensitive.test (1241 of 2115)
PASS: lldb-shell :: Breakpoint/case-sensitive.test (1242 of 2115)
PASS: lldb-shell :: Breakpoint/debug_addrx.test (1243 of 2115)

```

</details>

https://github.com/llvm/llvm-project/pull/134179