Robustify toolchain string matching

cmake/toolchains/Toolchain-posix-clang-native.cmake

@@ -1,95 +0,0 @@
-
-set(WARNINGS
-    -Wall
-    -Werror
-    -Wextra
-    -Wdouble-promotion
-    -Wshadow
-    -Wfloat-equal
-    -Wframe-larger-than=1024
-    -Wpointer-arith
-    -Wlogical-op
-    -Wmissing-declarations
-    -Wno-unused-parameter
-    -Werror=format-security
-    -Werror=array-bounds
-    -Wfatal-errors
-    -Wformat=1
-    -Werror=unused-but-set-variable
-    -Werror=unused-variable
-    -Werror=double-promotion
-    -Werror=reorder
-    -Werror=uninitialized
-    -Werror=init-self
-    -Werror=return-type
-    -Werror=deprecated
-    -Werror=unused-private-field
-    -Wno-packed
-    -Wno-frame-larger-than=
-    -Wno-varargs
-    #-Wcast-qual  - generates spurious noreturn attribute warnings,
-    #               try again later
-    #-Wconversion - would be nice, but too many "risky-but-safe"
-    #               conversions in the code
-    #-Wcast-align - would help catch bad casts in some cases,
-    #               but generates too many false positives
-    )
-
-set(OPT_FLAGS
-	-Os -g3
-	)
-
-#=============================================================================
-#		c flags
-#
-set(C_WARNINGS
-	-Wbad-function-cast
-	-Wstrict-prototypes
-	-Wold-style-declaration
-	-Wmissing-parameter-type
-	-Wmissing-prototypes
-	-Wnested-externs
-	)
-set(C_FLAGS
-	-std=gnu99
-	-fno-common
-	-fsanitize=address
-	-fno-omit-frame-pointer
-	)
-
-#=============================================================================
-#		cxx flags
-#
-set(CXX_WARNINGS
-	-Wno-missing-field-initializers
-	-Wno-varargs
-	)
-set(CXX_FLAGS
-	-fno-exceptions
-	-fno-rtti
-	-std=gnu++0x
-	-fno-threadsafe-statics
-	-fsanitize=address
-	-fno-omit-frame-pointer
-	-DCONFIG_WCHAR_BUILTIN
-	-D__CUSTOM_FILE_IO__
-	)
-
-#=============================================================================
-#		ld flags
-#
-set(LD_FLAGS
-	-fsanitize=address
-	-Wl,--warn-common
-	-Wl,--gc-sections
-	)
-
-#=============================================================================
-#		misc flags
-#
-set(VISIBILITY_FLAGS
-	-fvisibility=hidden
-	"-include ${CMAKE_SOURCE_DIR}/src/include/visibility.h"
-	)
-set(EXE_LINK_FLAGS)
-