Using the -M flag causes several test cases to fail

[snoopyjc]

Using the -M flag causes several test cases to fail. Specifically:

✔️issue_45
✔️issue_66
issue_s106 - suspect my $sdp in block on line 10 is keeping global $sdp - loop ctr on line 32 from getting initialized
✔️issue_s148
✔️issue_s158
issue_s252 - issue with sub call on line 148 not detected as modifying the loop counter
issue_s275 - loop ctr $t in line 6 becomes main.t_l, but referenced as t_l in line 14
✔️issue_s30a
issue_s79 - issue is that on line 9 in _f9, finish() is slipping in a 'return' and convert_return_expression isn't being called
✔️issue_s95
✔️test_comments
✔️test_regex - issue is that on line 38 _substitute_global is inserted in handle_assignment_in_expression, but it doesn't handle the E flag we inserted
✔️test_s_tr - issue is on line 154 that $arr[$i++] =~ s/x/d/;, where i is main.i_v, gets incremented twice, and the _substitute_element replacement isn't being done. Same issue on line 158 for $arr[$i++] =~ tr/d/z/; with _translate_element.
✔️test_traceback
✔️issue_s140 - MATCH_MULTIPLE_LINES isn't being initialized (to 0).