[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, 4 insertions, 0 deletions

diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index 8574d0a7e81..935c64a0fa1 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -429,6 +429,10 @@ private:
       return "ConstraintNormalization";
     case CodeSynthesisContext::ParameterMappingSubstitution:
       return "ParameterMappingSubstitution";
+    case CodeSynthesisContext::RequirementInstantiation:
+      return "RequirementInstantiation";
+    case CodeSynthesisContext::NestedRequirementConstraintsCheck:
+      return "NestedRequirementConstraintsCheck";
     }
     return "";
   }