libc: Move per-arch sys/Makefile.inc to libsys

libc/<arch>/sys/Makefile.inc -> libsys/<arch>/Makefile.sys.

Require that libsys/<arch>/Makefile.sys exist.  At least for current
archtiectures, it's not possible for an architecture to not have and MD
syscall bits.

powerpcspe/Makefile.sys's structure means it had to be modified when moved
so rename detection won't work, but it has trivial contents so the
history is unimportant.

Reviewed by:	kib, emaste, imp
Pull Request:	https://github.com/freebsd/freebsd-src/pull/908

lib/libc/Makefile

@@ -123,7 +123,6 @@ NOASM=
 .include "${LIBC_SRCTOP}/softfloat/Makefile.inc"
 .endif
 .if ${LIBC_ARCH} == "i386" || ${LIBC_ARCH} == "amd64"
-.include "${LIBC_SRCTOP}/x86/sys/Makefile.inc"
 .include "${LIBC_SRCTOP}/x86/gen/Makefile.inc"
 .endif
 .if ${MK_NIS} != "no"

lib/libc/powerpcspe/sys/Makefile.inc

@@ -1,2 +0,0 @@
-.PATH: ${LIBSYS_SRCTOP}/powerpc
-.sinclude "${LIBC_SRCTOP}/powerpc/sys/Makefile.inc"

lib/libsys/Makefile.sys

@@ -20,7 +20,10 @@ NOASM=	exit.o \
 	yield.o
 PSEUDO=	_exit.o \
 	_getlogin.o
-.sinclude "${LIBC_SRCTOP}/${LIBC_ARCH}/sys/Makefile.inc"
+.include "${LIBSYS_SRCTOP}/${LIBC_ARCH}/Makefile.sys"
+.if ${LIBC_ARCH} == "i386" || ${LIBC_ARCH} == "amd64"
+.include "${LIBSYS_SRCTOP}/x86/Makefile.sys"
+.endif
 
 SRCS+= clock_gettime.c gettimeofday.c __vdso_gettimeofday.c
 NOASM+=  clock_gettime.o gettimeofday.o

lib/libsys/arm/Makefile.sys

@@ -1,4 +1,4 @@
 SRCS+=	__vdso_gettc.c \
 	sched_getcpu_gen.c
 
-MDASM= vfork.S cerror.S syscall.S
+MDASM=	vfork.S cerror.S syscall.S

lib/libsys/powerpcspe/Makefile.sys

@@ -0,0 +1,7 @@
+CFLAGS+= -I${LIBC_SRCTOP}/powerpc
+CFLAGS+= -I${LIBSYS_SRCTOP}/powerpc
+
+SYM_MAPS+=	${LIBSYS_SRCTOP}/powerpc/Symbol.map
+
+.PATH: ${LIBSYS_SRCTOP}/powerpc
+.include "${LIBSYS_SRCTOP}/powerpc/Makefile.sys"