Add gmonster-{1,2} perf testcases.

These testcases are mocks of real programs.
GDB doesn't care what the programs do, they just have to look
and/or behave like the real program.
These testcases exercise gdb when debugging really large programs.
E.g., gmonster-1 has 10,000 CUs, and gmonster-2 has 1000 shared libs
(which is actually a little small, 5000 would be more accurate).

gdb/testsuite/ChangeLog:

	* gdb.perf/lib/perftest/utils.py: New file.
	* gdb.perf/gm-hello.cc: New file.
	* gdb.perf/gm-pervasive-typedef.cc: New file.
	* gdb.perf/gm-pervasive-typedef.h: New file.
	* gdb.perf/gm-std.cc: New file.
	* gdb.perf/gm-std.h: New file.
	* gdb.perf/gm-use-cerr.cc: New file.
	* gdb.perf/gm-utils.h: New file.
	* gdb.perf/gmonster-null-lookup.py: New file.
	* gdb.perf/gmonster-pervasive-typedef.py: New file.
	* gdb.perf/gmonster-print-cerr.py: New file.
	* gdb.perf/gmonster-ptype-string.py: New file.
	* gdb.perf/gmonster-runto-main.py: New file.
	* gdb.perf/gmonster-select-file.py: New file.
	* gdb.perf/gmonster1-null-lookup.exp: New file.
	* gdb.perf/gmonster1-pervasive-typedef.exp: New file.
	* gdb.perf/gmonster1-print-cerr.exp: New file.
	* gdb.perf/gmonster1-ptype-string.exp: New file.
	* gdb.perf/gmonster1-runto-main.exp: New file.
	* gdb.perf/gmonster1-select-file.exp: New file.
	* gdb.perf/gmonster1.cc: New file.
	* gdb.perf/gmonster1.exp: New file.
	* gdb.perf/gmonster2-null-lookup.exp: New file.
	* gdb.perf/gmonster2-pervasive-typedef.exp: New file.
	* gdb.perf/gmonster2-print-cerr.exp: New file.
	* gdb.perf/gmonster2-ptype-string.exp: New file.
	* gdb.perf/gmonster2-runto-main.exp: New file.
	* gdb.perf/gmonster2-select-file.exp: New file.
	* gdb.perf/gmonster2.cc: New file.
	* gdb.perf/gmonster2.exp: New file.

gdb/testsuite/gdb.perf/lib/perftest/utils.py

@@ -0,0 +1,68 @@
+# Copyright (C) 2015 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import gdb
+
+def safe_execute(command):
+    """Execute command, ignoring any gdb errors."""
+    result = None
+    try:
+        result = gdb.execute(command, to_string=True)
+    except gdb.error:
+        pass
+    return result
+
+
+def convert_spaces(file_name):
+    """Return file_name with all spaces replaced with "-"."""
+    return file_name.replace(" ", "-")
+
+
+def select_file(file_name):
+    """Select a file for debugging.
+
+    N.B. This turns confirmation off.
+    """
+    safe_execute("set confirm off")
+    print ("Selecting file %s" % (file_name))
+    if file_name is None:
+        gdb.execute("file")
+    else:
+        gdb.execute("file %s" % (file_name))
+
+
+def runto(location):
+    """Run the program to location.
+
+    N.B. This turns confirmation off.
+    """
+    safe_execute("set confirm off")
+    gdb.execute("tbreak %s" % (location))
+    gdb.execute("run")
+
+
+def runto_main():
+    """Run the program to "main".
+
+    N.B. This turns confirmation off.
+    """
+    runto("main")
+
+
+def run_n_times(count, func):
+    """Execute func count times."""
+    while count > 0:
+        func()
+        count -= 1