[CMake] Rename `SANITIZER_HEADERS` to `SANITIZER_IMPL_HEADERS` under `lib/sanitizer_common`.

[delcypher]

Summary

[CMake] Rename SANITIZER_HEADERS to SANITIZER_IMPL_HEADERS under lib/sanitizer_common.

The variable name SANITIZER_HEADERS is already used for the list of
public headers in include/CMakeLists.txt. Although the previous
implementation worked it's probably best to avoid shadowing global
variables to avoid confusion.

[delcypher]

@george.karpenkov Thanks for approving.

compiler-rt/trunk/lib/sanitizer_common/CMakeLists.txt

set(SANITIZER_SYMBOLIZER_SOURCES
   sanitizer_symbolizer_report.cc
   sanitizer_symbolizer_win.cc
   sanitizer_unwind_linux_libcdep.cc
   sanitizer_unwind_win.cc)
 
 # Explicitly list all sanitizer_common headers. Not all of these are
 # included in sanitizer_common source files, but we need to depend on
 # headers when building our custom unit tests.
-set(SANITIZER_HEADERS
+set(SANITIZER_IMPL_HEADERS
   sancov_flags.h
   sancov_flags.inc
   sanitizer_addrhashmap.h
   sanitizer_allocator.h
   sanitizer_allocator_bytemap.h
   sanitizer_allocator_checks.h
   sanitizer_allocator_combined.h
   sanitizer_allocator_interface.h

 if(APPLE)
   set(OS_OPTION OS ${SANITIZER_COMMON_SUPPORTED_OS})
 endif()
 
 add_compiler_rt_object_libraries(RTSanitizerCommon
   ${OS_OPTION}
   ARCHS ${SANITIZER_COMMON_SUPPORTED_ARCH}
   SOURCES ${SANITIZER_SOURCES}
-  ADDITIONAL_HEADERS ${SANITIZER_HEADERS}
+  ADDITIONAL_HEADERS ${SANITIZER_IMPL_HEADERS}
   CFLAGS ${SANITIZER_CFLAGS}
   DEFS ${SANITIZER_COMMON_DEFINITIONS})
 add_compiler_rt_object_libraries(RTSanitizerCommonNoTermination
   ${OS_OPTION}
   ARCHS ${SANITIZER_COMMON_SUPPORTED_ARCH}
   SOURCES ${SANITIZER_SOURCES_NOTERMINATION}
-  ADDITIONAL_HEADERS ${SANITIZER_HEADERS}
+  ADDITIONAL_HEADERS ${SANITIZER_IMPL_HEADERS}
   CFLAGS ${SANITIZER_CFLAGS}
   DEFS ${SANITIZER_COMMON_DEFINITIONS})
 add_compiler_rt_object_libraries(RTSanitizerCommonNoLibc
   ${OS_OPTION}
   ARCHS ${SANITIZER_COMMON_SUPPORTED_ARCH}
   SOURCES ${SANITIZER_NOLIBC_SOURCES}
-  ADDITIONAL_HEADERS ${SANITIZER_HEADERS}
+  ADDITIONAL_HEADERS ${SANITIZER_IMPL_HEADERS}
   CFLAGS ${SANITIZER_CFLAGS}
   DEFS ${SANITIZER_COMMON_DEFINITIONS})
 add_compiler_rt_object_libraries(RTSanitizerCommonLibc
   ${OS_OPTION}
   ARCHS ${SANITIZER_COMMON_SUPPORTED_ARCH}
   SOURCES ${SANITIZER_LIBCDEP_SOURCES}
-  ADDITIONAL_HEADERS ${SANITIZER_HEADERS}
+  ADDITIONAL_HEADERS ${SANITIZER_IMPL_HEADERS}
   CFLAGS ${SANITIZER_CFLAGS}
   DEFS ${SANITIZER_COMMON_DEFINITIONS})
 add_compiler_rt_object_libraries(RTSanitizerCommonCoverage
   ${OS_OPTION}
   ARCHS ${SANITIZER_COMMON_SUPPORTED_ARCH}
   SOURCES ${SANITIZER_COVERAGE_SOURCES}
-  ADDITIONAL_HEADERS ${SANITIZER_HEADERS}
+  ADDITIONAL_HEADERS ${SANITIZER_IMPL_HEADERS}
   CFLAGS ${SANITIZER_CFLAGS}
   DEFS ${SANITIZER_COMMON_DEFINITIONS})
 add_compiler_rt_object_libraries(RTSanitizerCommonSymbolizer
   ${OS_OPTION}
   ARCHS ${SANITIZER_COMMON_SUPPORTED_ARCH}
   SOURCES ${SANITIZER_SYMBOLIZER_SOURCES}
-  ADDITIONAL_HEADERS ${SANITIZER_HEADERS}
+  ADDITIONAL_HEADERS ${SANITIZER_IMPL_HEADERS}
   CFLAGS ${SANITIZER_CFLAGS}
   DEFS ${SANITIZER_COMMON_DEFINITIONS})
 
 set(SANITIZER_NO_WEAK_HOOKS_CFLAGS ${SANITIZER_CFLAGS})
 list(APPEND SANITIZER_NO_WEAK_HOOKS_CFLAGS "-DSANITIZER_SUPPORTS_WEAK_HOOKS=0")
 add_compiler_rt_object_libraries(RTSanitizerCommonNoHooks
   ${OS_OPTION}
   ARCHS ${SANITIZER_COMMON_SUPPORTED_ARCH}
   SOURCES ${SANITIZER_SOURCES}
-  ADDITIONAL_HEADERS ${SANITIZER_HEADERS}
+  ADDITIONAL_HEADERS ${SANITIZER_IMPL_HEADERS}
   CFLAGS ${SANITIZER_NO_WEAK_HOOKS_CFLAGS}
   DEFS ${SANITIZER_COMMON_DEFINITIONS})
 add_compiler_rt_object_libraries(RTSanitizerCommonLibcNoHooks
   ${OS_OPTION}
   ARCHS ${SANITIZER_COMMON_SUPPORTED_ARCH}
   SOURCES ${SANITIZER_LIBCDEP_SOURCES}
-  ADDITIONAL_HEADERS ${SANITIZER_HEADERS}
+  ADDITIONAL_HEADERS ${SANITIZER_IMPL_HEADERS}
   CFLAGS ${SANITIZER_NO_WEAK_HOOKS_CFLAGS}
   DEFS ${SANITIZER_COMMON_DEFINITIONS})
 add_compiler_rt_object_libraries(RTSanitizerCommonSymbolizerNoHooks
   ${OS_OPTION}
   ARCHS ${SANITIZER_COMMON_SUPPORTED_ARCH}
   SOURCES ${SANITIZER_SYMBOLIZER_SOURCES}
-  ADDITIONAL_HEADERS ${SANITIZER_HEADERS}
+  ADDITIONAL_HEADERS ${SANITIZER_IMPL_HEADERS}
   CFLAGS ${SANITIZER_NO_WEAK_HOOKS_CFLAGS}
   DEFS ${SANITIZER_COMMON_DEFINITIONS})
 
 if(OS_NAME MATCHES "SunOS")
   # Solaris ld doesn't support the non-standard GNU ld extension of adding
   # __start_SECNAME and __stop_SECNAME labels to sections whose names are
   # valid C identifiers.  Instead we add our own definitions for the
   # __sancov_guards section.

compiler-rt/trunk/lib/sanitizer_common/tests/CMakeLists.txt

set(SANITIZER_UNITTESTS
   sanitizer_test_main.cc
   sanitizer_thread_registry_test.cc
   sanitizer_vector_test.cc)
 
 set(SANITIZER_TEST_HEADERS
   sanitizer_pthread_wrappers.h
   sanitizer_test_config.h
   sanitizer_test_utils.h)
-foreach(header ${SANITIZER_HEADERS})
+foreach(header ${SANITIZER_IMPL_HEADERS})
   list(APPEND SANITIZER_TEST_HEADERS ${CMAKE_CURRENT_SOURCE_DIR}/../${header})
 endforeach()
 
 set(SANITIZER_TEST_CFLAGS_COMMON
   ${COMPILER_RT_UNITTEST_CFLAGS}
   ${COMPILER_RT_GTEST_CFLAGS}
   -I${COMPILER_RT_SOURCE_DIR}/include
   -I${COMPILER_RT_SOURCE_DIR}/lib