Changes to make openzfs build within FreeBSD buildworld

A collection of header changes to enable FreeBSD to build
with vendored OpenZFS.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10635

lib/libspl/asm-i386/atomic.S

@@ -28,8 +28,12 @@
 	.file	"%M%"
 
 #define _ASM
+#ifdef __linux__
 #include <ia32/sys/asm_linkage.h>
-
+#elif __FreeBSD__
+#include <machine/asmacros.h>
+#define SET_SIZE(x)
+#endif
 	ENTRY(atomic_inc_8)
 	ALTENTRY(atomic_inc_uchar)
 	movl	4(%esp), %eax

lib/libspl/include/os/freebsd/sys/param.h

@@ -45,8 +45,10 @@
  */
 #define	MAXNAMELEN	256
 
+#ifndef IN_BASE
 #define	UID_NOBODY	60001		/* user ID no body */
 #define	GID_NOBODY	UID_NOBODY
+#endif
 #define	UID_NOACCESS	60002		/* user ID no access */
 
 #define	MAXUID		UINT32_MAX	/* max user id */

lib/libspl/include/rpc/xdr.h

@@ -40,10 +40,13 @@
 
 #define	XDR_GET_BYTES_AVAIL 1
 
-typedef struct xdr_bytesrec {
+#ifndef HAVE_XDR_BYTESREC
+struct xdr_bytesrec {
 	bool_t xc_is_last_record;
 	size_t xc_num_avail;
-} xdr_bytesrec_t;
+};
+#endif
+typedef struct xdr_bytesrec  xdr_bytesrec_t;
 
 /*
  * This functionality is not required and is disabled in user space.

lib/libspl/include/sys/isa_defs.h

@@ -208,7 +208,7 @@ extern "C" {
 #error MIPS no endian specified
 #endif
 
-#ifndef _LP64
+#if !defined(_LP64) && !defined(_ILP32)
 #define	_ILP32
 #endif
 

lib/libspl/include/sys/uio.h

@@ -141,7 +141,8 @@ static inline offset_t
 uio_index_at_offset(uio_t *uio, offset_t off, uint_t *vec_idx)
 {
 	*vec_idx = 0;
-	while (*vec_idx < uio_iovcnt(uio) && off >= uio_iovlen(uio, *vec_idx)) {
+	while (*vec_idx < (uint_t)uio_iovcnt(uio) &&
+	    off >= (offset_t)uio_iovlen(uio, *vec_idx)) {
 		off -= uio_iovlen(uio, *vec_idx);
 		(*vec_idx)++;
 	}