Summary:
This change implements support for image selectors and image selector
specifications as described in section 9.6.
In check-coarray[.h,cpp] I changed the `Leave()` function for
`parser::ImageSelectorSpec` to take a `parser::ImageSelector`, which
contains a list of image selector specifications. This allows us to
detect when the same specification is used more than once. I also added
code to analyze the expressions for the image selector specifications to
expression.cpp and a test for all of the conditions to check at
compile-time.
Note that we do not check at compile-time to see if the value of the
cosubscripts are within the specified cobounds. We also do not check anything
related to selecting a valid team. We also do not check that the denotation of
the `stat-variable` is not dependent on the evaluation of an entity in the
same statement.
Reviewers: klausler, tskeith, DavidTruby
Subscribers: llvm-commits
Tags: #llvm, #flang
Differential Revision: https://reviews.llvm.org/D83336