Fixup PRSVADDR problem as per Johns suggestions.

gdb/procfs.c

@@ -2041,7 +2041,7 @@ child_resume (step, signo)
   errno = 0;
   pi.prrun.pr_flags = PRSTRACE | PRSFAULT | PRCFAULT;
 
-#if !defined(sun) && !defined(sparc)
+#ifdef PRSVADDR_BROKEN
 /* Can't do this under Solaris running on a Sparc, as there seems to be no
    place to put nPC.  In fact, if you use this, nPC seems to be set to some
    random garbage.  We have to rely on the fact that PC and nPC have been

gdb/xm-sun4sol2.h

@@ -62,3 +62,6 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 /* May be needed, may be not?  From Pace Willisson's port.  FIXME.  */
 #define NEED_POSIX_SETPGID
+
+/* Solaris PSRVADDR support does not seem to include a place for nPC.  */
+#define PRSVADDR_BROKEN