[C++] Do not explicitly set O0 for Debug builds.

Author: denizevrenci

CMakeLists.txt

@@ -82,7 +82,6 @@ find_package(Threads)
 
 if(UNIX)
     add_compile_options(-Wall -Wpedantic -Wextra -Wno-unused-parameter)
-    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -O0")
     set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -Ofast")
 endif()