Introduce some new MI test suite cleanups for breakpoint and
breakpoint table handling.  This is a patch in five parts (all committed
here in one commit).

----- 1/5: parse_args
parse_args is a very useful utility function which allows you to do
getopt-y kinds of things in Tcl.

Example:
proc myproc {foo args} {
        parse_args {{bar} {baz "abc"} {qux}}
          # ...
}
myproc ABC -bar -baz DEF peanut butter

will define the following variables in myproc:
foo (=ABC), bar (=1), baz (=DEF), and qux (=0)
args will be the list {peanut butter}

----- 2/5: mi_build_kv_pairs
build_kv_pairs simply does what it says: given the input list
and an option join string, it combines list elements into kv-pairs
for MI handling.  It knows how to handle tuples and other special
MI types.

Example:
mi_build_kv_pairs {a b c d e f g \[.*\]}
returns a=\"b\",c=\"d\",e=\"f\",g=\[.*\]

----- 3/5: mi_make_breakpoint
This function builds breakpoint regexps, such as
"bkpt={number=\".*\", [snip]}".

Note that ONLY the options given to mi_make_breakpoint/mi_create_breakpoint
will actually be tested. So if -number is omitted, the regexp will allow
anything [number=\".*\"]

Examples:
mi_make_breakpoint -number 3

mi_create_breakpoint "myfile.c:21" -file myfile.c -line 21

----- 4/5: mi_make_breakpoint_table
This function builds MI breakpoint table regexps.

Example:
set bps {}
lappend bps [mi_make_breakpoint -number 1 -func "main" \
    -file ".*/myfile.c" -line 42
lappend bps [mi_make_breakpoint -number 2 -func "marker" \
    -file ".*myfile.c" -line 21
gdb_test "-break-info" "\\^done,[mi_make_breakpoint_table $bps]" \
    "breakpoint list"

----- 5/5: Update all callers
Self-explanatory

testsuite/ChangeLog
2014-04-23  Keith Seitz  <keiths@redhat.com>

	* lib/mi-support.exp (mi_list_breakpoints): Delete.
	(mi_make_breakpoint_table): New procedure.
	(mi_create_breakpoint): Use mi_make_breakpoint
	and return the result.
	(mi_make_breakpoint): New procedure.
	(mi_build_kv_pairs): New procedure.

	* gdb.mi/mi-break.exp: Remove unused globals,
	update mi_create_breakpoint usage, and use mi_make_breakpoint_table.
	All callers updated.
	* gdb.mi/mi-dprintf.exp: Use variable to track command
	number.
	Update all callers of mi_create_breakpoint and use
	mi_make_breakpoint_table.
	Remove any unused global variables.
	* gdb.mi/mi-nonstop.exp: Likewise.
	* gdb.mi/mi-nsintrall.exp: Likewise.
	* gdb.mi/mi-nsmoribund.exp: Likewise.
	* gdb.mi/mi-nsthrexec.exp: Likewise.
	* gdb.mi/mi-reverse.exp: Likewise.
	* gdb.mi/mi-simplerun.exp: Likewise.
	* gdb.mi/mi-stepn.exp: Likewise.
	* gdb.mi/mi-syn-frame.exp: Likewise.
	* gdb.mi/mi-until.exp: Likewise.
	* gdb.mi/mi-var-cp.exp: Likewise.
	* gdb.mi/mi-var-display.exp: Likewise.
	* gdb.mi/mi2-amd64-entry-value.exp: Likewise.
	* gdb.mi/mi2-var-child.exp: Likewise.
	* gdb.mi/mi-vla-c99.exp: Likewise.
	* lib/mi-support.exp: Likewise.

	From Ian Lance Taylor  <iant@cygnus.com>:
	* lib/gdb.exp (parse_args): New procedure.