systemc: Teach verify.py to filter messages which start within a line.

It's possible for a test to generate a warning or error in the middle
of a line of output. The previous filter generator function would
create a filter which would only detect those messages which started
at the beginning of a new line.

Change-Id: I40372dc33049df84f3111e4d63a6619db97dcaa3
Reviewed-on: https://gem5-review.googlesource.com/c/12597
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/systemc/tests/verify.py

@@ -192,7 +192,7 @@ class Checker(object):
             return test_f.read() == ref_f.read()
 
 def tagged_filt(tag, num):
-    return (r'^\n{}: \({}{}\) .*\n(In file: .*\n)?'
+    return (r'\n{}: \({}{}\) .*\n(In file: .*\n)?'
             r'(In process: [\w.]* @ .*\n)?').format(tag, tag[0], num)
 
 def error_filt(num):