Rework the code used to check for calls to impure procedures in DO CONCURRENT
constructs. The current code wasn't checking the representation of the
procedure references in the strongly typed expressions, so it was missing
calls to impure subprograms made via generic interfaces. While here,
improve error messages, and fix some minor issues exposed by testing the
improved checks.
Differential Revision: https://reviews.llvm.org/D155489
The purity or impurity of a call to a generic interface
depends on the attributes of the specific procedure or specific
binding. Change expression analysis of calls to generic interfaces
to replace the symbol in the parse tree with the specific procedure
or binding; this ensures that later checking for purity in
DO CONCURRENT and other contexts will be accurate.
Remove an "XFAIL" from a test that now passes again with this fix.
Differential Revision: https://reviews.llvm.org/D126150
