Flag recursive make targets with .MAKE

so that job token pipe is passed to them.
To avoid surprising anyone, only add .MAKE to ${TGTS} when -n
has not been specified (at least for Makefile).

Reviewed by:	obrien

Makefile

@@ -209,6 +209,12 @@ cleanworld:
 # Handle the user-driven targets, using the source relative mk files.
 #
 
+.if empty(.MAKEFLAGS:M-n)
+# skip this for -n to avoid changing previous behavior of 
+# 'make -n buildworld' etc.
+${TGTS}: .MAKE
+.endif
+
 ${TGTS}:
 	${_+_}@cd ${.CURDIR}; ${_MAKE} ${.TARGET}
 

Makefile.inc1

@@ -1890,3 +1890,5 @@ _xi-links:
 xdev xdev-build xdev-install:
 	@echo "*** Error: Both XDEV and XDEV_ARCH must be defined for \"${.TARGET}\" target"
 .endif
+
+buildkernel ${WMAKE_TGTS} ${.ALLTARGETS:M_*}: .MAKE