The OpenACC standard says side-effects/ordering of expressions in
clauses and constructs (not yet, but PR for constructs) cannot be
depended on. We already had infrastructure to ensure constructs, and
non-template clauses did this right, but we had the ordering of a call
vs transform of the clauses happened in tree transform.
This patch ensures that the evaluation context put together for the
construct covers the clauses as well in tree transform.
'wait' takes a few int-exprs (well, a series of async-arguments, but
those are effectively just an int-expr), plus a pair of tags. This
patch adds the support for this to the AST, and does the appropriate
semantic analysis for them.
This is a pretty simple clause, it takes an 'async-argument', which
effectively needs to be just parsed as an 'int' argument, since it can
be an arbitrarly integer at runtime (and negative values are legal for
implementation defined values).
This patch also cleans up the async-argument parsing, so 'wait' got some
minor quality-of-life improvements for parsing (both clause and
construct).
num_gangs takes an 'int-expr-list', for 'parallel', and an 'int-expr'
for 'kernels'. This patch changes the parsing to always parse it as an
'int-expr-list', then correct the expression count during Sema. It also
implements the rest of the semantic analysis changes for this clause.
The 'vector_length' clause is semantically identical to the
'num_workers' clause, in that it takes a mandatory single int-expr. This
is implemented identically to it.