hardcode_minus_L on HP-UX 11.23/IA-64

[Albert Chin]

>From ld(1) on HP-UX 11.23/IA-64:
  +[no]defaultrpath
       +defaultrpath is the default.  Include any paths
       that are specified with -L in the embedded path,
       unless you specify the +b option.  If you use +b,
       only the path list specified by +b is in the
       embedded path.

       The +nodefaultrpath option removes all library
       paths that were specified with the -L option from
       the embedded path.  The linker searches the
       library paths specified by the -L option at link
       time.  At run time, the only library paths
       searched are those specified by the environment
       variables LD_LIBRARY_PATH and SHLIB_PATH, library
       paths specified by the +b linker option, and
       finally the default library paths.

So, hardcode_minus_L=yes is incorrect on this platform if
+nodefaultrpath is in LDFLAGS. Should we set hardcode_minus_L=yes only
when there is no +nodefaultrpath (similar to how we set
aix_use_runtimelinking=yes when LDFLAGS has -brtl in it)? We should
probably do this only when the compiler and linker driver are the
same.

-- 
albert chin (address@hidden)