[compiler-rt] Change the CMake build to generate full debugging info when COMPILER_RT_DEBUG=ON

[kubamracek]

Summary

The compiler-rt CMake build currently uses -gline-tables-only for all builds. While this makes the debugger correctly map source files, debugging of the runtime libraries in general is pretty tough, because you don't see any local variables, parameters, etc. Let's allow emitting full debugging info by setting COMPILER_RT_DEBUG=ON.

[samsonov]

LGTM

[kubamracek]

Landed in r224749.

CMakeLists.txt

 
 # Build with optimization, unless we're in debug mode. If we're using MSVC,
 # always respect the optimization flags set by CMAKE_BUILD_TYPE instead.
 if(NOT COMPILER_RT_DEBUG AND NOT MSVC)
   list(APPEND SANITIZER_COMMON_CFLAGS -O3)
 endif()
 
 # Build sanitizer runtimes with debug info.
-if(COMPILER_RT_HAS_GLINE_TABLES_ONLY_FLAG)
+if(COMPILER_RT_HAS_GLINE_TABLES_ONLY_FLAG AND NOT COMPILER_RT_DEBUG)
   list(APPEND SANITIZER_COMMON_CFLAGS -gline-tables-only)
 elseif(COMPILER_RT_HAS_G_FLAG)
   list(APPEND SANITIZER_COMMON_CFLAGS -g)
 elseif(COMPILER_RT_HAS_Zi_FLAG)
   list(APPEND SANITIZER_COMMON_CFLAGS /Zi)
 endif()
 
 # Turn off several warnings.