[runtimes] Serialize all Lit params instead of passing them to add_lit_testsuite

[ldionne]

Summary

add_lit_testsuite() takes Lit parameters passed to it and adds them
to the parameters used globally when running all test suites. That
means that a target like check-all, which ends up calling Lit on
the whole monorepo, will see the test parameters for all the individual
project's test suites.

So, for example, it would see --param std=c++03 (from libc++abi), and
--param std=c++03 (from libc++), and --param whatever (from another
project being tested at the same time). While always unclean, that works
when the parameters all agree. However, if the parameters share the same
name but have different values, only one of those two values will be used
and it will be incredibly confusing to understand why one of the test
suites is being run with the incorrect parameter value.

For that reason, this commit moves away from using add_lit_testsuite()'s
PARAM functionality, and serializes the parameter values for the runtimes
in the generated config.py file instead, which is local to the specific
test suite.

[ldionne]

Rebase onto main for CI.

libcxx/test/CMakeLists.txt

 if (LLVM_USE_SANITIZER)
   serialize_lit_param(use_sanitizer "\"${LLVM_USE_SANITIZER}\"")
 endif()
 
 if (LIBCXX_BUILD_32_BITS)
   serialize_lit_param(enable_32bit True)
 endif()
 
+foreach(param IN LISTS LIBCXX_TEST_PARAMS)
+  string(REGEX REPLACE "(.+)=(.+)" "\\1" name "${param}")
+  string(REGEX REPLACE "(.+)=(.+)" "\\2" value "${param}")
+  serialize_lit_param("${name}" "\"${value}\"")
+endforeach()
+
 if (NOT DEFINED LIBCXX_TEST_DEPS)
   message(FATAL_ERROR "Expected LIBCXX_TEST_DEPS to be defined")
 endif()
 
 if (LIBCXX_INCLUDE_TESTS)
   include(AddLLVM) # for configure_lit_site_cfg and add_lit_testsuite
 
   configure_lit_site_cfg(
     "${LIBCXX_TEST_CONFIG}"
     ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
     MAIN_CONFIG "${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py")
 
   add_custom_target(cxx-test-depends
     DEPENDS cxx ${LIBCXX_TEST_DEPS}
     COMMENT "Builds dependencies required to run the test suite.")
 
   add_lit_testsuite(check-cxx
     "Running libcxx tests"
     ${CMAKE_CURRENT_BINARY_DIR}
-    DEPENDS cxx-test-depends
-    PARAMS "${LIBCXX_TEST_PARAMS}")
+    DEPENDS cxx-test-depends)
 endif()
 
 if (LIBCXX_GENERATE_COVERAGE)
   include(CodeCoverage)
   set(output_dir "${CMAKE_CURRENT_BINARY_DIR}/coverage")
   set(capture_dirs
       "${LIBCXX_LIB_CMAKEFILES_DIR}/cxx_objects.dir/"
       "${LIBCXX_LIB_CMAKEFILES_DIR}/cxx.dir/"

libcxxabi/test/CMakeLists.txt

 if (TARGET_TRIPLE)
   serialize_lit_param(target_triple "\"${TARGET_TRIPLE}\"")
 endif()
 
 if (LIBCXXABI_BUILD_32_BITS)
   serialize_lit_param(enable_32bit True)
 endif()
 
+foreach(param IN LISTS LIBCXXABI_TEST_PARAMS)
+  string(REGEX REPLACE "(.+)=(.+)" "\\1" name "${param}")
+  string(REGEX REPLACE "(.+)=(.+)" "\\2" value "${param}")
+  serialize_lit_param("${name}" "\"${value}\"")
+endforeach()
+
 configure_lit_site_cfg(
   "${LIBCXXABI_TEST_CONFIG}"
   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
   MAIN_CONFIG "${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py")
 
 add_lit_testsuite(check-cxxabi "Running libcxxabi tests"
   ${CMAKE_CURRENT_BINARY_DIR}
-  DEPENDS ${LIBCXXABI_TEST_DEPS}
-  PARAMS "${LIBCXXABI_TEST_PARAMS}")
+  DEPENDS ${LIBCXXABI_TEST_DEPS})

libunwind/test/CMakeLists.txt

 if (TARGET_TRIPLE)
   serialize_lit_param(target_triple "\"${TARGET_TRIPLE}\"")
 endif()
 
 if (LIBUNWIND_BUILD_32_BITS)
   serialize_lit_param(enable_32bit True)
 endif()
 
+foreach(param IN LISTS LIBUNWIND_TEST_PARAMS)
+  string(REGEX REPLACE "(.+)=(.+)" "\\1" name "${param}")
+  string(REGEX REPLACE "(.+)=(.+)" "\\2" value "${param}")
+  serialize_lit_param("${name}" "\"${value}\"")
+endforeach()
+
 configure_lit_site_cfg(
   "${LIBUNWIND_TEST_CONFIG}"
   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
   MAIN_CONFIG "${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py")
 
 add_lit_testsuite(check-unwind "Running libunwind tests"
   ${CMAKE_CURRENT_BINARY_DIR}
-  DEPENDS unwind ${LIBUNWIND_TEST_DEPS}
-  PARAMS "${LIBUNWIND_TEST_PARAMS}")
+  DEPENDS unwind ${LIBUNWIND_TEST_DEPS})