@heading unaffected by @lowersections

[Quinn Grier]

@heading and friends are unaffected by @lowersections. One would expect
the following to output Foo and Bar at the same sectioning level, as is
the case without the @lowersections command:

      \input texinfo
      @setfilename test.info
      @settitle test
      @lowersections
      @section Foo
      @heading Bar
      @bye

However, Bar is output one level higher than Foo. This is easy to see in
the HTML produced by texi2any --html --no-split, where Foo uses <h4> and
Bar uses <h3>. This happens with texi2any (GNU texinfo) 6.0 and 5.2, but
it seems to work properly on an older makeinfo (GNU texinfo) 4.13.

Quinn Grier