Add $CC_MKDEP to override $CC and the -c option

build/mkdep

@@ -29,7 +29,7 @@ set -e				# exit immediately if any errors occur
 
 MAKE=Makefile			# default makefile name is "Makefile"
 NOSLASH="no"			# by default, / dependencies are included
-CC=${CC-cc}				# default compiler is cc
+CC=${CC_MKDEP-${CC-cc}}		# default compiler is cc
 : ${CC_MKDEP_FLAGS="-M"}	# cc -M usually produces dependencies
 SRCDIR=""
 SED=cat
@@ -53,7 +53,7 @@ while :
 
 		# -c allows you to select a compiler to use (default is cc)
 		-c)
-			CC=$2
+			[ -z "$CC_MKDEP" ] && CC=$2
 			shift; shift ;;
 
 		# the -p flag produces "program: program.c" style dependencies