[runtimes] Avoid cluttering the top-level build directory with test artifacts (#112717)

Instead of placing artifacts for testing the runtimes at <build>/test,
place those artifacts at <build>/<project>/test. This prevents
cluttering the build directory with the runtimes' test artifacts for
everyone else.

As a drive-by, remove LIBCXX_BINARY_INCLUDE_DIR which wasn't used
anymore.

Author: ldionne

libcxx/CMakeLists.txt

@@ -19,7 +19,6 @@ set(CMAKE_FOLDER "libc++")
 
 set(LIBCXX_SOURCE_DIR  ${CMAKE_CURRENT_SOURCE_DIR})
 set(LIBCXX_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
-set(LIBCXX_BINARY_INCLUDE_DIR "${LIBCXX_BINARY_DIR}/include/c++build")
 
 include(GNUInstallDirs)
 include(WarningFlags)
@@ -443,8 +442,6 @@ else()
       "Path where target-specific libc++ headers should be installed.")
 endif()
 
-file(MAKE_DIRECTORY "${LIBCXX_BINARY_INCLUDE_DIR}")
-
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBCXX_LIBRARY_DIR})
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${LIBCXX_LIBRARY_DIR})
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${LIBCXX_LIBRARY_DIR})

libcxx/test/configs/cmake-bridge.cfg.in

@@ -20,7 +20,7 @@ config.name = os.path.basename('@LIBCXX_TEST_CONFIG@')
 config.test_source_root = os.path.join('@LIBCXX_SOURCE_DIR@', 'test')
 config.test_format = libcxx.test.format.CxxStandardLibraryTest()
 config.recursiveExpansionLimit = 10
-config.test_exec_root = os.path.join('@CMAKE_BINARY_DIR@', 'test')
+config.test_exec_root = os.path.join('@LIBCXX_BINARY_DIR@', 'test')
 
 # Add substitutions for bootstrapping the test suite configuration
 config.substitutions.append(('%{libcxx-dir}', '@LIBCXX_SOURCE_DIR@'))

libcxxabi/test/configs/cmake-bridge.cfg.in

@@ -21,7 +21,7 @@ config.name = os.path.basename('@LIBCXXABI_TEST_CONFIG@')
 config.test_source_root = os.path.join('@LIBCXXABI_SOURCE_DIR@', 'test')
 config.test_format = libcxx.test.format.CxxStandardLibraryTest()
 config.recursiveExpansionLimit = 10
-config.test_exec_root = os.path.join('@CMAKE_BINARY_DIR@', 'test')
+config.test_exec_root = os.path.join('@LIBCXXABI_BINARY_DIR@', 'test')
 
 # TODO: This is a non-standard Lit attribute and we should have another way of accessing this.
 config.host_triple = '@LLVM_HOST_TRIPLE@'

libunwind/test/configs/cmake-bridge.cfg.in

@@ -20,7 +20,7 @@ config.name = os.path.basename('@LIBUNWIND_TEST_CONFIG@')
 config.test_source_root = os.path.join('@LIBUNWIND_SOURCE_DIR@', 'test')
 config.test_format = libcxx.test.format.CxxStandardLibraryTest()
 config.recursiveExpansionLimit = 10
-config.test_exec_root = os.path.join('@CMAKE_BINARY_DIR@', 'test')
+config.test_exec_root = os.path.join('@LIBUNWIND_BINARY_DIR@', 'test')
 
 # Add a few features that are common to all the configurations
 if @LIBUNWIND_USES_ARM_EHABI@: