validate_info_seg bug in diagnosing Usage sections in subroutine info_segs

[Gary Dixon]

An earlier change to validate_info_seg [approve(1985-11-04,MCR7289)] was implemented incorrectly,
leading to a subtle bug when validating info segments containing a "Syntax" title. Subroutine and subsystem request info segments use this title. While most subroutine info segs appear to be handled OK, all subsystem request info segments are diagnosed a UNKNOWN FORMAT.

For example:

>t>vis mb

>user_dir_dir>Multics>GDixon>work>vis_for_mbuild>mb.info

-----------COMMAND info
LINE: 1     :Info: mbuild: mb:  2020-01-27  mbuild, mb
LINE: 3     Syntax as a command
LINE: 6     Function
LINE: 22    Control arguments

-----------GENERAL info
LINE: 63    :Info: summary.gi: summary: 2020-02-02  mbuild Requests
LINE: 65    Summary of requests
Severity 2, line 65. Paragraph size (20 lines) exceeds limit of 15.
Severity 3. These lines of section exceed 71 chars:  67,  68,  70,  73,  74,  76,  78,  80,
          82,  83,  84,  87,  91,  93,  95,  100

-----------UNKNOWN format info
LINE: 103   :Info: scan: sc:  2020-01-25  scan, sc
LINE: 105   Syntax
LINE: 109   Function
LINE: 113   Control arguments

-----------UNKNOWN format info
LINE: 123   :Info: read: rd:  2020-01-26  read, rd
LINE: 125   Syntax
LINE: 129   Function
LINE: 135   Control arguments

The problem involves the "19Syntax" element of the std_section array, and the USAGE constant, which is used as a section_index value.

This problem should be repaired so that subsystem request info segments are properly validated.

[Gary Dixon]

validate_info_segment is now obsolete. That tool was replaced by the verify_info (vi) command. I am therefore closing this bug as wont fix.