Set .ORDER for makesyscalls generated files

When either makesyscalls.lua or syscalls.master changes, all of the
${GENERATED} targets are now out-of-date. With make jobs > 1, this means we
will run the makesyscalls script in parallel for the same ABI, generating
the same set of output files.

Prior to r356603 , there is a large window for interlacing output for some
of the generated files that we were generating in-place rather than staging
in a temp dir. After that, we still should't need to run the script more
than once per-ABI as the first invocation should update all of them. Add
.ORDER to do so cleanly.

Reviewed by:	brooks
Discussed with:	sjg
Differential Revision:	https://reviews.freebsd.org/D23099

sys/amd64/linux/Makefile

@@ -19,6 +19,9 @@ GENERATED=	linux_proto.h		\
 all:
 	@echo "make sysent only"
 
+# We .ORDER these explicitly so that we only run MAKESYSCALLS once, rather than
+# potentially once for each ${GENERATED} file.
+.ORDER: ${GENERATED}
 sysent: ${GENERATED}
 
 ${GENERATED}: ${MAKESYSCALLS} ${SRCS}

sys/amd64/linux32/Makefile

@@ -19,6 +19,9 @@ GENERATED=	linux32_proto.h		\
 all:
 	@echo "make sysent only"
 
+# We .ORDER these explicitly so that we only run MAKESYSCALLS once, rather than
+# potentially once for each ${GENERATED} file.
+.ORDER: ${GENERATED}
 sysent: ${GENERATED}
 
 ${GENERATED}: ${MAKESYSCALLS} ${SRCS}

sys/arm/linux/Makefile

@@ -19,6 +19,9 @@ GENERATED=	linux_proto.h		\
 all:
 	@echo "make sysent only"
 
+# We .ORDER these explicitly so that we only run MAKESYSCALLS once, rather than
+# potentially once for each ${GENERATED} file.
+.ORDER: ${GENERATED}
 sysent: ${GENERATED}
 
 ${GENERATED}: ${MAKESYSCALLS} ${SRCS}

sys/arm64/linux/Makefile

@@ -19,6 +19,9 @@ GENERATED=	linux_proto.h		\
 all:
 	@echo "make sysent only"
 
+# We .ORDER these explicitly so that we only run MAKESYSCALLS once, rather than
+# potentially once for each ${GENERATED} file.
+.ORDER: ${GENERATED}
 sysent: ${GENERATED}
 
 ${GENERATED}: ${MAKESYSCALLS} ${SRCS}

sys/compat/cloudabi32/Makefile

@@ -17,6 +17,9 @@ GENERATED=	cloudabi32_proto.h	\
 all:
 	@echo "make sysent only"
 
+# We .ORDER these explicitly so that we only run MAKESYSCALLS once, rather than
+# potentially once for each ${GENERATED} file.
+.ORDER: ${GENERATED}
 sysent: ${GENERATED}
 
 ${GENERATED}: ${MAKESYSCALLS} ${SRCS}

sys/compat/cloudabi64/Makefile

@@ -17,6 +17,9 @@ GENERATED=	cloudabi64_proto.h	\
 all:
 	@echo "make sysent only"
 
+# We .ORDER these explicitly so that we only run MAKESYSCALLS once, rather than
+# potentially once for each ${GENERATED} file.
+.ORDER: ${GENERATED}
 sysent: ${GENERATED}
 
 ${GENERATED}: ${MAKESYSCALLS} ${SRCS}

sys/compat/freebsd32/Makefile

@@ -20,6 +20,9 @@ GENERATED=	freebsd32_proto.h		\
 all:
 	@echo "make sysent only"
 
+# We .ORDER these explicitly so that we only run MAKESYSCALLS once, rather than
+# potentially once for each ${GENERATED} file.
+.ORDER: ${GENERATED}
 sysent: ${GENERATED}
 
 ${GENERATED}: ${MAKESYSCALLS} ${SRCS}

sys/i386/linux/Makefile

@@ -19,6 +19,9 @@ GENERATED=	linux_proto.h		\
 all:
 	@echo "make sysent only"
 
+# We .ORDER these explicitly so that we only run MAKESYSCALLS once, rather than
+# potentially once for each ${GENERATED} file.
+.ORDER: ${GENERATED}
 sysent: ${GENERATED}
 
 ${GENERATED}: ${MAKESYSCALLS} ${SRCS}

sys/kern/Makefile

@@ -21,6 +21,9 @@ GENERATED=	init_sysent.c		\
 all:
 	@echo "make sysent only"
 
+# We .ORDER these explicitly so that we only run MAKESYSCALLS once, rather than
+# potentially once for each ${GENERATED} file.
+.ORDER: ${GENERATED}
 sysent: ${GENERATED}
 
 ${GENERATED}: ${MAKESYSCALLS} ${SRCS}