[mlir-cpu-runner] Add `export_executable_symbols` in CMake
This patch is primarily about the change in
"mlir/tools/mlir-cpu-runner/CMakeLists.txt". LLJIT needs access to
symbols (e.g. llvm_orc_registerEHFrameSectionWrapper) that will be
defined in the executable when LLVM is linked statically. This change is
consistent with how other tools within LLVM use LLJIT. It is required to
make sure that:
```
$ mlir-cpu-runner --host-supports-jit
```
correctly returns `true` on platforms that do support JITting (in my
case that's AArch64 Linux).
The change in "mlir/lib/ExecutionEngine/CMakeLists.txt" is required to
avoid ODR violations when symbols from `mlir-cpu-runner` are exported
and when loading `libmlir_async_runtime.so` in `mlir-cpu-runner`.
Specifically, to avoid `EnableABIBreakingChecks` being defined twice.
For more context:
* https://github.com/llvm/llvm-project/issues/61712
* https://github.com/llvm/llvm-project/issues/61856
* https://reviews.llvm.org/D146935 (this PR)
This change relands
ccdcfad0815296d8952438632d9abe6bc0a5258a
Fixes #61856
Differential Revision: https://reviews.llvm.org/D146935