Touch c-gperf.h before building legacy gcc.

build/scripts/build_cross_tools

@@ -124,8 +124,9 @@ copy_headers $haikuSourceDir/headers/posix $tmpIncludeDir/posix
 
 # Touch some files generated by bison, so that bison won't run to update them.
 # Fixes issues with newer bison versions.
+# And while at it, touch gperf target, too (as gperf may not be installed)
 (cd $buildToolsDir/gcc/gcc; touch c-parse.c c-parse.h cexp.c cp/parse.c \
-	cp/parse.h)
+	cp/parse.h c-gperf.h)
 
 # configure gcc
 cd $gccObjDir