introduce LONE_CHAR (optimized strcmp with one-char string)

coreutils/Kbuild

@@ -10,6 +10,7 @@ lib-y:=
 lib-$(CONFIG_BASENAME)  += basename.o
 lib-$(CONFIG_CAL)       += cal.o
 lib-$(CONFIG_CAT)       += cat.o
+lib-$(CONFIG_LESS)      += cat.o # less uses it if stdout isn't a tty
 lib-$(CONFIG_CATV)      += catv.o
 lib-$(CONFIG_CHGRP)     += chgrp.o chown.o
 lib-$(CONFIG_CHMOD)     += chmod.o
@@ -28,6 +29,7 @@ lib-$(CONFIG_DIRNAME)   += dirname.o
 lib-$(CONFIG_DOS2UNIX)  += dos2unix.o
 lib-$(CONFIG_DU)        += du.o
 lib-$(CONFIG_ECHO)      += echo.o
+lib-$(CONFIG_ASH)       += echo.o # used by ash
 lib-$(CONFIG_ENV)       += env.o
 lib-$(CONFIG_EXPR)      += expr.o
 lib-$(CONFIG_FALSE)     += false.o
@@ -65,6 +67,7 @@ lib-$(CONFIG_SYNC)      += sync.o
 lib-$(CONFIG_TAIL)      += tail.o
 lib-$(CONFIG_TEE)       += tee.o
 lib-$(CONFIG_TEST)      += test.o
+lib-$(CONFIG_ASH)       += test.o # used by ash
 lib-$(CONFIG_TOUCH)     += touch.o
 lib-$(CONFIG_TR)        += tr.o
 lib-$(CONFIG_TRUE)      += true.o