[flang][runtime] Let more list-directed child input advance (#160590)

Whether list-directed child READ statements should be allowed to advance
to further records is neither explicit in the standard nor consistent in
existing Fortran implementations. We allow child namelist READ
statements to advance, but not other list- directed child input.

This patch refines our interpretation of this case. Child namelist READ
statements continue to be able to advance; in addition, non-namelist
child READ statements can now advance if their parent READ statement is
a list-directed input statement at the top level, or a child that could.
But non-namelist list-directed child input taking place in a context
with explicit format control won't advance to following records, so that
the format-controlled parent READ statement can retain control over
record advancement.

Also corrects two cases of record repositioning in numeric input
editing, which were failing under child input because they weren't
allowing for left tab limits.

Fixes https://github.com/llvm/llvm-project/issues/160351.

0 files changed, 0 insertions, 0 deletions