[AST][3/4] Move the bit-fields from BlockDecl, LinkageSpecDecl and OMPDeclareReductionDecl into DeclContext

This patch follows https://reviews.llvm.org/D49729
and https://reviews.llvm.org/D49732, and is
followed by https://reviews.llvm.org/D49734.

Move the bits from BlockDecl, LinkageSpecDecl and
OMPDeclareReductionDecl into DeclContext.

Differential Revision: https://reviews.llvm.org/D49733

Patch By: bricci

llvm-svn: 338639
diff --git a/clang/lib/AST/DeclOpenMP.cpp b/clang/lib/AST/DeclOpenMP.cpp
index f5c3599..eaf88de 100644
--- a/clang/lib/AST/DeclOpenMP.cpp
+++ b/clang/lib/AST/DeclOpenMP.cpp
@@ -57,6 +57,14 @@
 // OMPDeclareReductionDecl Implementation.
 //===----------------------------------------------------------------------===//
 
+OMPDeclareReductionDecl::OMPDeclareReductionDecl(
+    Kind DK, DeclContext *DC, SourceLocation L, DeclarationName Name,
+    QualType Ty, OMPDeclareReductionDecl *PrevDeclInScope)
+    : ValueDecl(DK, DC, L, Name, Ty), DeclContext(DK), Combiner(nullptr),
+      PrevDeclInScope(PrevDeclInScope) {
+  setInitializer(nullptr, CallInit);
+}
+
 void OMPDeclareReductionDecl::anchor() {}
 
 OMPDeclareReductionDecl *OMPDeclareReductionDecl::Create(