This patch fixes the "Format string required" error when trying to print
a dprintf on a now resolved, pending location when set via the MI interface
even if the format string is entered correctly.
This patch also adds a test case to check that issue called
mi-dprintf-pending.exp.
gdb/ChangeLog:
PR breakpoints/16465
* breakpoint.c (create_breakpoint): Save extra_string for
pending breakpoints.
gdb/testsuite/ChangeLog:
PR breakpoints/16465
* gdb.mi/mi-dprintf-pending.c: New file.
* gdb.mi/mi-dprintf-pending.exp: New test.
* gdb.mi/mi-dprintf-pendshr.c: New file.
