[CMake] Rename check-clang-tools to check-clang-tools-extra

[phosek]

Summary

Match the top-level project name (that is the name developers would use
in LLVM_ENABLE_PROJECTS) with the name of the target, and provide alias
for backwards compatibility.

[smeenai]

LGTM.

If you care about eventually getting rid of the old check-clang-tools alias, you'd want to have a mailing list announcement/deprecation notices/etc. (I don't think leaving it around does any harm though.)

Might want to add a release notes entry?

[smeenai]

clang-tools-extra/test/CMakeLists.txt

81

Nit: You need an explicit "'s" now (as in "Clang tools extra's regression tests"), since "extra" doesn't end with an s.

87

Same here.

clang-tools-extra/test/CMakeLists.txt

set(LLVM_UTILS_DEPS
   FileCheck count not
 )
 foreach(dep ${LLVM_UTILS_DEPS})
   if(TARGET ${dep})
     list(APPEND CLANG_TOOLS_TEST_DEPS ${dep})
   endif()
 endforeach()
 
-add_lit_testsuite(check-clang-tools "Running the Clang extra tools' regression tests"
+add_lit_testsuite(check-clang-tools-extra "Running the Clang tools extra' regression tests"
   ${CMAKE_CURRENT_BINARY_DIR}
   DEPENDS ${CLANG_TOOLS_TEST_DEPS}
   ARGS ${CLANG_TOOLS_TEST_EXTRA_ARGS}
   )
 
-set_target_properties(check-clang-tools PROPERTIES FOLDER "Clang extra tools' tests")
+set_target_properties(check-clang-tools-extra PROPERTIES FOLDER "Clang tools extra' tests")
 
-add_lit_testsuites(CLANG-EXTRA ${CMAKE_CURRENT_SOURCE_DIR}
+add_lit_testsuites(CLANG-TOOLS-EXTRA ${CMAKE_CURRENT_SOURCE_DIR}
   DEPENDS ${CLANG_TOOLS_TEST_DEPS}
   )
+
+# Provide `check-clang-tools` alias for backwards compatibility.
+add_custom_target(check-clang-tools)
+add_dependencies(check-clang-tools check-clang-tools-extra)