This removes the specialized parsers and helper classes for these
clauses, namely ConcatSeparated, MapModifiers, and MotionModifiers. Map
and the motion clauses are now handled in the same way as all other
clauses with modifiers, with one exception: the commas separating their
modifiers are optional. This syntax is deprecated in OpenMP 5.2.
Implement version checks for modifiers: for a given modifier on a given
clause, check if that modifier is allowed on this clause in the
specified OpenMP version. This replaced several individual checks.
Add a testcase for handling map modifiers in a different order, and for
diagnosing an ultimate modifier out of position.
This is the first part of the effort to make parsing of clause modifiers
more uniform and robust. Currently, when multiple modifiers are allowed,
the parser will expect them to appear in a hard-coded order.
Additionally, modifier properties (such as "ultimate") are checked
separately for each case.
The overall plan is
1. Extract all modifiers into their own top-level classes, and then
equip them with sets of common properties that will allow performing the
property checks generically, without refering to the specific kind of
the modifier.
2. Define a parser (as a separate class) for each modifier.
3. For each clause define a union (std::variant) of all allowable
modifiers, and parse the modifiers as a list of these unions.
The intent is also to isolate parts of the code that could eventually be
auto-generated.
OpenMP modifier overhaul: #1/3
This prepares for using the DECLARE MAPPER construct.
A check in lowering will say "Not implemented" when trying to use a
mapper as some code is required to tie the mapper to the declared one.
Senantics check for the symbol generated.
Define `OmpIteratorSpecifier` and `OmpIteratorModifier` parser classes,
and add parsing for them. Those are reusable between any clauses that
use iterator modifiers.
Add support for iterator modifiers to the MAP clause up to lowering,
where a TODO message is emitted.
The convention is to use enum names that match the source spelling (up
to upper/lower case), including names with underscores.
Remove the special case from unparser, update tests.
This commit adds parsing of type modifiers for the MAP clause: CLOSE,
OMPX_HOLD, and PRESENT. The support for ALWAYS has already existed.
The new modifiers are not yet handled in lowering: when present, a TODO
message is emitted and compilation stops.
