"source", foreground execution commands, and target-async

Sourcing a GDB script that runs foreground execution commands in
succession fails if the target can async:

 Breakpoint 1, main () at ../../../src/gdb/testsuite/gdb.base/source-execution.c:36
 36        func1 ();
 (gdb) source ../../../src/gdb/testsuite/gdb.base/source-execution.gdb
 ../../../src/gdb/testsuite/gdb.base/source-execution.gdb:21: Error in sourced command file:
 Cannot execute this command while the selected thread is running.
 (gdb) FAIL: gdb.base/source-execution.exp: source source-execution.gdb

That is, after a foreground execution command, GDB moves on to the
following command immediately before waiting for the previous command
to complete.

https://sourceware.org/ml/gdb-patches/2011-09/msg00037.html (b4a14fd0)
addressed this for command lists, Python's gdb.execute, etc., but
missed "source".  Fixed now in the same way.

gdb/
2014-03-25  Pedro Alves  <palves@redhat.com>

	* cli/cli-script.c (script_from_file): Force the interpreter to
	sync mode.

gdb/testsuite/
2014-03-25  Pedro Alves  <palves@redhat.com>
	    Doug Evans  <dje@google.com>

	* gdb.base/source-execution.c: New file.
	* gdb.base/source-execution.exp: New file.
	* gdb.base/source-execution.gdb: New file.

1 files changed, 41 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.base/source-execution.c b/gdb/testsuite/gdb.base/source-execution.c
new file mode 100644
index 0000000..e7de119
--- /dev/null
+++ b/gdb/testsuite/gdb.base/source-execution.c
@@ -0,0 +1,41 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2014 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/>.  */
+
+static void
+func1 (void)
+{
+}
+
+static void
+func2 (void)
+{
+}
+
+static void
+func3 (void)
+{
+}
+
+int
+main (void)
+{
+  func1 ();
+  func2 ();
+  func3 ();
+
+  return 0;
+}