buildroot/toolchain/gcc/Config.in.2

config BR2_PACKAGE_GCC_TARGET
	bool "native toolchain in the target filesystem"
	default n
	help
	  If you want the target system to be able to run
	  binutils/gcc and compile native code, say Y here.

config BR2_EXTRA_TARGET_GCC_CONFIG_OPTIONS
	string "Additional target gcc options"
	default ""
	depends BR2_PACKAGE_GCC_TARGET
	help
	  Any additional target gcc options you may want to include....
	  Including, but not limited to --disable-checking etc.
	  Refer to */configure in your gcc sources.