branches/zip: Minor changes which allow build with UNIV_HOTBACKUP

defined to succeed:

include/trx0sys.h: Allow Hot Backup build to see some
                   TRX_SYS_DOUBLEWRITE_... macros. 
trx/trx0sys.c:     Exclude trx_sys_close() function from Hot Backup build.
log/log0recv.[ch]: Exclude recv_sys_var_init() function from Hot Backup build.

This change should not affect !UNIV_HOTBACKUP build.

include/log0recv.h

@@ -258,12 +258,14 @@ void
 recv_sys_init(
 /*==========*/
 	ulint	available_memory);	/*!< in: available memory in bytes */
+#ifndef UNIV_HOTBACKUP
 /********************************************************//**
 Reset the state of the recovery system variables. */
 UNIV_INTERN
 void
 recv_sys_var_init(void);
 /*===================*/
+#endif /* !UNIV_HOTBACKUP */
 /*******************************************************************//**
 Empties the hash table of stored log records, applying them to appropriate
 pages. */

include/trx0sys.h

@@ -333,12 +333,14 @@ UNIV_INTERN
 void
 trx_sys_file_format_tag_init(void);
 /*==============================*/
+#ifndef UNIV_HOTBACKUP
 /*****************************************************************//**
 Shutdown/Close the transaction system. */
 UNIV_INTERN
 void
 trx_sys_close(void);
 /*===============*/
+#endif /* !UNIV_HOTBACKUP */
 /*****************************************************************//**
 Get the name representation of the file format from its id.
 @return	pointer to the name */
@@ -495,7 +497,6 @@ this contains the same fields as TRX_SYS_MYSQL_LOG_INFO below */
 						within that file */
 #define TRX_SYS_MYSQL_LOG_NAME		12	/*!< MySQL log file name */
 
-#ifndef UNIV_HOTBACKUP
 /** Doublewrite buffer */
 /* @{ */
 /** The offset of the doublewrite buffer header on the trx system header page */
@@ -547,6 +548,7 @@ FIL_PAGE_ARCH_LOG_NO_OR_SPACE_NO. */
 #define TRX_SYS_DOUBLEWRITE_BLOCK_SIZE	FSP_EXTENT_SIZE
 /* @} */
 
+#ifndef UNIV_HOTBACKUP
 /** File format tag */
 /* @{ */
 /** The offset of the file format tag on the trx system header page

log/log0recv.c

@@ -239,6 +239,7 @@ recv_sys_mem_free(void)
 	}
 }
 
+#ifndef UNIV_HOTBACKUP
 /************************************************************
 Reset the state of the recovery system variables. */
 UNIV_INTERN
@@ -278,6 +279,7 @@ recv_sys_var_init(void)
 
 	recv_max_page_lsn = 0;
 }
+#endif /* !UNIV_HOTBACKUP */
 
 /************************************************************
 Inits the recovery system for a recovery operation. */

trx/trx0sys.c

@@ -1535,6 +1535,7 @@ trx_sys_file_format_id_to_name(
 
 #endif /* !UNIV_HOTBACKUP */
 
+#ifndef UNIV_HOTBACKUP
 /*********************************************************************
 Shutdown/Close the transaction system. */
 UNIV_INTERN
@@ -1611,3 +1612,4 @@ trx_sys_close(void)
 	trx_sys = NULL;
 	mutex_exit(&kernel_mutex);
 }
+#endif /* !UNIV_HOTBACKUP */