Unify Assembler files between Linux and Windows

Add new macro ASMABI used by Windows to change
calling API to "sysv_abi".

Reviewed-by: Attila Fülöp <attila@fueloep.org>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Closes #14228

include/Makefile.am

@@ -20,6 +20,7 @@ COMMON_H = \
 	sys/aggsum.h \
 	sys/arc.h \
 	sys/arc_impl.h \
+	sys/asm_linkage.h \
 	sys/avl.h \
 	sys/avl_impl.h \
 	sys/bitops.h \