build failure on HP-UX 11.11

[Greg Wooledge]

GNU m4 1.4.13 fails to build on HP-UX 11.11:

make[4]: Entering directory `/usr/local/src/m4-1.4.13/lib'
 CC  gl_avltree_oset.o
In file included from sys/wait.h:91,
                 from sys/wait.h:28,
                 from stdlib.h:307,
                 from stdlib.h:34,
                 from gl_avltree_oset.c:25:
sys/resource.h:106: error: field `ru_utime' has incomplete type
sys/resource.h:107: error: field `ru_stime' has incomplete type

Line 106 of that file is "struct timeval ru_utime;" plus a comment.

I worked around this by editing the generated ./lib/sys/time.h file.
Before:

# if 0
#  include_next <sys/time.h>
# endif

After:

# if 1
#  include_next <sys/time.h>
# endif

After making that change, it was able to build, and passed the vast
majority of the "make check" test suite.

I'm using a prebuilt gcc 3.4 20030730 (experimental) compiler; m4 is
part of the toolchain bootstrap process on the way to building my own
gcc from source.