ENH: Adding build type flags for C.

Modules/Platform/gcc.cmake

@@ -4,3 +4,7 @@ SET (CMAKE_CXX_FLAGS_MINSIZEREL_INIT "-O3")
 SET (CMAKE_CXX_FLAGS_RELEASE_INIT "-O2")
 SET (CMAKE_CXX_FLAGS_RELWITHDEBINFO_INIT "-O2 -g")
 SET (CMAKE_C_FLAGS_INIT "")
+SET (CMAKE_C_FLAGS_DEBUG_INIT "-g")
+SET (CMAKE_C_FLAGS_MINSIZEREL_INIT "-O3")
+SET (CMAKE_C_FLAGS_RELEASE_INIT "-O2")
+SET (CMAKE_C_FLAGS_RELWITHDEBINFO_INIT "-O2 -g")