[llvm] Add unit tests for size returning new funcs in the MemProf use pass. (PR #105473)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-ppc64le-rhel` running on `ppc64le-clang-rhel-test` while building `llvm` at step 7 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/145/builds/1479

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

```
Step 7 (test-build-unified-tree-check-all) failure: test (failure)
...
0.163 [1/2/2] Building CXX object compiler-rt/lib/ubsan/CMakeFiles/RTUbsan_dynamic_version_script_dummy.powerpc64le.dir/dummy.cpp.o
0.361 [0/2/3] Linking CXX shared library /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/lib/clang/20/lib/powerpc64le-unknown-linux-gnu/libclang_rt.ubsan_standalone.so
0.387 [0/1/4] Linking CXX shared library /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/lib/clang/20/lib/powerpc64le-unknown-linux-gnu/libclang_rt.asan.so
23.933 [5/5/1167] cd /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/runtimes/runtimes-bins && /home/buildbots/llvm-external-buildbots/cmake-3.28.2/bin/cmake --build /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/runtimes/runtimes-bins/ --target runtimes-test-depends --config Release
ninja: no work to do.
23.997 [4/5/1168] No install step for 'runtimes'
24.020 [3/5/1170] Completed 'runtimes'
35.449 [3/4/1171] Building CXX object unittests/ProfileData/CMakeFiles/ProfileDataTests.dir/CoverageMappingTest.cpp.o
37.778 [3/3/1172] Building CXX object unittests/Transforms/Instrumentation/CMakeFiles/InstrumentationTests.dir/MemProfilerTest.cpp.o
37.833 [2/3/1173] Linking CXX executable unittests/Transforms/Instrumentation/InstrumentationTests
FAILED: unittests/Transforms/Instrumentation/InstrumentationTests 
: && /home/docker/llvm-external-buildbots/clang.17.0.6/bin/clang++ --gcc-toolchain=/gcc-toolchain/usr -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -Wl,--color-diagnostics     -Wl,--gc-sections unittests/Transforms/Instrumentation/CMakeFiles/InstrumentationTests.dir/PGOInstrumentationTest.cpp.o unittests/Transforms/Instrumentation/CMakeFiles/InstrumentationTests.dir/MemProfilerTest.cpp.o -o unittests/Transforms/Instrumentation/InstrumentationTests  -Wl,-rpath,/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/lib  lib/libLLVMPasses.so.20.0git  -lpthread  lib/libllvm_gtest_main.so.20.0git  -lpthread  lib/libLLVMTestingSupport.so.20.0git  lib/libLLVMInstrumentation.so.20.0git  lib/libLLVMAnalysis.so.20.0git  lib/libLLVMAsmParser.so.20.0git  lib/libLLVMCore.so.20.0git  lib/libllvm_gtest.so.20.0git  lib/libLLVMSupport.so.20.0git  -Wl,-rpath-link,/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/lib && :
ld.lld: error: undefined symbol: llvm::memprof::getHotColdSchema()
>>> referenced by MemProfilerTest.cpp
>>>               unittests/Transforms/Instrumentation/CMakeFiles/InstrumentationTests.dir/MemProfilerTest.cpp.o:(llvm::memprof::(anonymous namespace)::MemProfilerTest_AnnotatesCall_Test::TestBody())

ld.lld: error: undefined symbol: vtable for llvm::IndexedMemProfReader
>>> referenced by MemProfilerTest.cpp
>>>               unittests/Transforms/Instrumentation/CMakeFiles/InstrumentationTests.dir/MemProfilerTest.cpp.o:(.toc+0x38)
>>> the vtable symbol may be undefined because the class is missing its key function (see https://lld.llvm.org/missingkeyfunction)
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
38.153 [2/2/1174] Building CXX object unittests/ProfileData/CMakeFiles/ProfileDataTests.dir/MemProfTest.cpp.o
45.778 [2/1/1175] Building CXX object unittests/ProfileData/CMakeFiles/ProfileDataTests.dir/InstrProfTest.cpp.o
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/105473