libzpool: move zfs_context_os.h from libspl

Keeping the spl/zfs module split, libzpool is the zfs module for
userspace. Headers and functions specific to it belong there.

Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes #17861

config/Rules.am

@@ -10,7 +10,8 @@ AM_CPPFLAGS = \
 	-I$(top_srcdir)/include \
 	-I$(top_srcdir)/module/icp/include \
 	-I$(top_srcdir)/lib/libspl/include \
-	-I$(top_srcdir)/lib/libspl/include/os/@ac_system_l@
+	-I$(top_srcdir)/lib/libspl/include/os/@ac_system_l@ \
+	-I$(top_srcdir)/lib/libzpool/include
 
 AM_LIBTOOLFLAGS = --silent
 

lib/libspl/include/Makefile.am

@@ -65,7 +65,6 @@ libspl_sys_HEADERS = \
 	%D%/sys/uio.h \
 	%D%/sys/vnode.h \
 	%D%/sys/wmsum.h \
-	%D%/sys/zfs_context_os.h \
 	%D%/sys/zone.h
 
 libspl_ia32dir = $(libspldir)/sys/ia32

lib/libzpool/Makefile.am

@@ -1,3 +1,5 @@
+include $(srcdir)/%D%/include/Makefile.am
+
 libzpool_la_CFLAGS  = $(AM_CFLAGS) $(KERNEL_CFLAGS) $(LIBRARY_CFLAGS)
 libzpool_la_CFLAGS += $(ZLIB_CFLAGS)
 

lib/libzpool/include/Makefile.am

@@ -0,0 +1,3 @@
+libzpool_sysdir = $(includedir)/libzpool/sys
+libzpool_sys_HEADERS = \
+	%D%/sys/zfs_context_os.h