testsuite: Fix subexpressions with `scan-assembler-times'

testsuite: Fix subexpressions with `scan-assembler-times'

We have an issue with `scan-assembler-times' handling expressions using
subexpressions as produced by capturing parentheses `()' in an odd way,
and one that is inconsistent with `scan-assembler', `scan-assembler-not',
etc.  The problem comes from calling `regexp' with `-inline -all', which
causes a list to be returned that would otherwise be placed in match
variables.

Consequently if we have say:

/* { dg-final { scan-assembler-times "\\s(foo|bar)\\s" 1 } } */

in a test case and there is a lone `foo' present in output being matched,
then our invocation of `regexp -inline -all' in `scan-assembler-times'
will return:

{ foo } foo

and that in turn will confuse our match count calculation as `llength'
will return 2 rather than 1, making the test fail even though `foo' was
only actually matched once.

It seems unclear why we chose to call `regexp' in such an odd way in the
first place just to figure out the number of matches.  The first version
of TCL that supports the `-all' option to `regexp' is 8.3, and according
to its documentation[1][2] `regexp' already returns the number of matches
found whenever `-all' has been used *unless* `-inline' has also been used.

Remove the `-inline' option then along with the `llength' invocation.

References:

[1] "Tcl Built-In Commands - regexp manual page",
    <https://www.tcl.tk/man/tcl8.2.3/TclCmd/regexp.html>

[2] "Tcl Built-In Commands - regexp manual page",
    <https://www.tcl.tk/man/tcl8.3/TclCmd/regexp.html>

	gcc/testsuite/
	* lib/scanasm.exp (scan-assembler-times): Remove the `-inline'
	option to `regexp' and the wrapping `llength' call.