wrong Tcl_StatBuf type with 64 HP Ansi C

When trying to build tcl on an HP system using HP's
optional ANSI C compiler (the default compiler that
comes with the system supports almost no features and
is suitable only for recompiling kernel table
declarations), many instances of the following error
pairs occur for files unix/tclUnixFile.c and
unix/tclUnixFCmd.c:

warning 604: Pointers are not assignment-compatible.
warning 563: Argument #2 is not the correct type.

In these files each calls to TclOSstat or TclOSlstat
generates this pair of errors.

Examining the results after pre-processing, but before
compiling reveals that the calls to Tcl_OSstat and
Tcl_OSlstat are being mapped to native calls stat and
lstat, respectively.

The function prototypes for both show a second argument
of type (stat *). The calling code passes an argument
of type (Tcl_StatBuf *), which is a typedef for (struct
stat64 *). There are 2 subtle differences between the
structures. First, member st_size is off_t (a typedef
for long), in stat, but off64_t, a typedef for
int64_t,. which is a typedef for long. This is
probably not a problem because the names are the same
and the base types are the same. Secondly, where stat
has member blckcnt_t, also of type off_t, stat64 has
member blckcnt64_t, of type int64_t. The base class is
the same for both, but the names are different.

OS details (uname -a): HP-UX urkel B.11.00 U 9000/800
1552710528 unlimited-user license

Compiler lines:

/usr/bin/cc -c -O -DTCL_DBGX= +z -I./../generic -I.
+DA2.0W -DPACKAGE_NAME=\"\" -DPACKAGE_TARNAME=\"\"
-DPACKAGE_VERSION=\"\" -DPACKAGE_STRING=\"\"
-DPACKAGE_BUGREPORT=\"\" -DSTDC_HEADERS=1
-DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1
-DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1
-DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1
-DHAVE_UNISTD_H=1 -DHAVE_UNISTD_H=1 -DHAVE_LIMITS_H=1
-DTCL_CFGVAL_ENCODING=\"iso8859-1\"
-D_LARGEFILE64_SOURCE=1 -DTCL_WIDE_INT_TYPE=long\ long
-DHAVE_STRUCT_STAT64=1 -DHAVE_TYPE_OFF64_T=1
-DWORDS_BIGENDIAN=1 -DHAVE_GETCWD=1 -DHAVE_OPENDIR=1
-DHAVE_STRSTR=1 -DHAVE_STRTOL=1 -DHAVE_TMPNAM=1
-DHAVE_WAITPID=1 -DHAVE_UNISTD_H=1 -DHAVE_SYS_PARAM_H=1
-DHAVE_SYS_MODEM_H=1 -DUSE_TERMIOS=1
-DHAVE_SYS_TIME_H=1 -DTIME_WITH_SYS_TIME=1
-DHAVE_TZNAME=1 -DHAVE_GMTIME_R=1 -DHAVE_LOCALTIME_R=1
-DHAVE_TIMEZONE_VAR=1 -DHAVE_STRUCT_STAT_ST_BLKSIZE=1
-DHAVE_ST_BLKSIZE=1 -DNO_UNION_WAIT=1 -DNO_GETTOD=1
-DHAVE_SIGNED_CHAR=1 -DHAVE_LANGINFO=1
-D_XOPEN_SOURCE=1 -D_XOPEN_SOURCE_EXTENDED=1
-DTCL_CFG_DO64BIT=1 -DTCL_CFG_OPTIMIZED=1
-DTCL_CFG_DEBUG=1 -DHAVE_SYS_IOCTL_H=1
-DTCL_SHLIB_EXT=\".sl\" ./../unix/tclUnixFCmd.c

/usr/bin/cc -c -O -DTCL_DBGX= +z -I./../generic -I.
+DA2.0W -DPACKAGE_NAME=\"\" -DPACKAGE_TARNAME=\"\"
-DPACKAGE_VERSION=\"\" -DPACKAGE_STRING=\"\"
-DPACKAGE_BUGREPORT=\"\" -DSTDC_HEADERS=1
-DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1
-DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1
-DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1
-DHAVE_UNISTD_H=1 -DHAVE_UNISTD_H=1 -DHAVE_LIMITS_H=1
-DTCL_CFGVAL_ENCODING=\"iso8859-1\"
-D_LARGEFILE64_SOURCE=1 -DTCL_WIDE_INT_TYPE=long\ long
-DHAVE_STRUCT_STAT64=1 -DHAVE_TYPE_OFF64_T=1
-DWORDS_BIGENDIAN=1 -DHAVE_GETCWD=1 -DHAVE_OPENDIR=1
-DHAVE_STRSTR=1 -DHAVE_STRTOL=1 -DHAVE_TMPNAM=1
-DHAVE_WAITPID=1 -DHAVE_UNISTD_H=1 -DHAVE_SYS_PARAM_H=1
-DHAVE_SYS_MODEM_H=1 -DUSE_TERMIOS=1
-DHAVE_SYS_TIME_H=1 -DTIME_WITH_SYS_TIME=1
-DHAVE_TZNAME=1 -DHAVE_GMTIME_R=1 -DHAVE_LOCALTIME_R=1
-DHAVE_TIMEZONE_VAR=1 -DHAVE_STRUCT_STAT_ST_BLKSIZE=1
-DHAVE_ST_BLKSIZE=1 -DNO_UNION_WAIT=1 -DNO_GETTOD=1
-DHAVE_SIGNED_CHAR=1 -DHAVE_LANGINFO=1
-D_XOPEN_SOURCE=1 -D_XOPEN_SOURCE_EXTENDED=1
-DTCL_CFG_DO64BIT=1 -DTCL_CFG_OPTIMIZED=1
-DTCL_CFG_DEBUG=1 -DHAVE_SYS_IOCTL_H=1
-DTCL_SHLIB_EXT=\".sl\" ./../unix/tclUnixFile.c

Config command line:

MAKE=gmake CC=/usr/bin/cc ./configure \ --enable-shared \ --enable-64bit \ --prefix=/usr/local/tcl-X/tcl8.5 \ --exec-prefix=/usr/local/tcl-X/tcl8.5

config.log attached.