[OpenACC] Implement 'reduction' sema for compute constructs (#92808)

'reduction' has a few restrictions over normal 'var-list' clauses:

1- On parallel, a num_gangs can only have 1 argument when combined with
reduction. These two aren't able to be combined on any other of the
compute constructs however.

2- The vars all must be 'numerical data types' types of some sort, or a
'composite of numerical data types'. A list of types is given in the
standard as a minimum, so we choose 'isScalar', which covers all of
these types and keeps types that are actually numeric. Other compilers
don't seem to implement the 'composite of numerical data types', though
we do.

3- Because of the above restrictions, member-of-composite is not
allowed, so any access via a memberexpr is disallowed. Array-element and
sub-arrays (aka array sections) are both permitted, so long as they meet
the requirements of #2.

This patch implements all of these for compute constructs.

1 files changed, 4 insertions, 0 deletions

diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index bfbdb5b..f00ba9e 100644
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -2855,6 +2855,10 @@ void OpenACCClauseEnqueue::VisitWaitClause(const OpenACCWaitClause &C) {
 }
 void OpenACCClauseEnqueue::VisitDeviceTypeClause(
     const OpenACCDeviceTypeClause &C) {}
+void OpenACCClauseEnqueue::VisitReductionClause(
+    const OpenACCReductionClause &C) {
+  VisitVarList(C);
+}
 } // namespace
 
 void EnqueueVisitor::EnqueueChildren(const OpenACCClause *C) {