[OpenACC] Add Compute Context Serialization test, fix a bug

While working on a followup patch, I discovered we didn't
serialize/deserialize the Compute Context properly, so this patch fixes
it, then adds a PCH mode to the ast test.

Author: erichkeane

clang/lib/Serialization/ASTReaderStmt.cpp

@@ -2805,7 +2805,7 @@ void ASTStmtReader::VisitOpenACCAssociatedStmtConstruct(
 
 void ASTStmtReader::VisitOpenACCComputeConstruct(OpenACCComputeConstruct *S) {
   VisitStmt(S);
-  VisitOpenACCConstructStmt(S);
+  VisitOpenACCAssociatedStmtConstruct(S);
 }
 
 //===----------------------------------------------------------------------===//

clang/lib/Serialization/ASTWriterStmt.cpp

@@ -2855,7 +2855,7 @@ void ASTStmtWriter::VisitOpenACCAssociatedStmtConstruct(
 
 void ASTStmtWriter::VisitOpenACCComputeConstruct(OpenACCComputeConstruct *S) {
   VisitStmt(S);
-  VisitOpenACCConstructStmt(S);
+  VisitOpenACCAssociatedStmtConstruct(S);
   Code = serialization::STMT_OPENACC_COMPUTE_CONSTRUCT;
 }
 

clang/test/SemaOpenACC/compute-construct-ast.cpp

@@ -1,5 +1,12 @@
 // RUN: %clang_cc1 %s -fopenacc -ast-dump | FileCheck %s
 
+// Test this with PCH.
+// RUN: %clang_cc1 %s -fopenacc -emit-pch -o %t %s
+// RUN: %clang_cc1 %s -fopenacc -include-pch %t -ast-dump-all | FileCheck %s
+
+#ifndef PCH_HELPER
+#define PCH_HELPER
+
 void NormalFunc() {
   // FIXME: Add a test once we have clauses for this.
   // CHECK-LABEL: NormalFunc
@@ -104,3 +111,5 @@ struct S {
 void use() {
   TemplFunc<S>();
 }
+#endif
+