others are untested and some are likely broken. add this config option before including config.mak rather than after so that the user can override it in config.mak if desired.
@@ -5,7 +5,7 @@ BINUTILS_SRCDIR = BINUTILS_SRCDIR_not_set
GCC_SRCDIR = GCC_SRCDIR_not_set
MUSL_SRCDIR = MUSL_SRCDIR_not_set
-COMMON_CONFIG =
+COMMON_CONFIG = --enable-languages=c,c++
GCC_CONFIG = $(COMMON_CONFIG)
TOOLCHAIN_CONFIG = $(GCC_CONFIG)