[Concepts] Requires Expressions

Implement support for C++2a requires-expressions.

Re-commit after compilation failure on some platforms due to alignment issues with PointerIntPair.

Differential Revision: https://reviews.llvm.org/D50360

(cherry picked from commit a0f50d731639350c7a79f140f026c27a18215531)

1 files changed, 2 insertions, 0 deletions

diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 6ee767ccecf..cb4d61cac2c 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -804,6 +804,7 @@ unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
     case OMPCapturedExpr:
     case Empty:
     case LifetimeExtendedTemporary:
+    case RequiresExprBody:
       // Never looked up by name.
       return 0;
   }
@@ -1177,6 +1178,7 @@ DeclContext *DeclContext::getPrimaryContext() {
   case Decl::Captured:
   case Decl::OMPDeclareReduction:
   case Decl::OMPDeclareMapper:
+  case Decl::RequiresExprBody:
     // There is only one DeclContext for these entities.
     return this;