SourceKit: Use getNextDepth()/getMaxDepth()

Author: slavapestov

lib/Sema/IDETypeCheckingRequests.cpp

@@ -215,7 +215,7 @@ static bool isMemberDeclAppliedInternal(const DeclContext *DC, Type BaseTy,
       module, VD->getDeclContext(), genericDecl->getGenericEnvironment());
 
   // The innermost generic parameters are mapped to error types.
-  unsigned innerDepth = genericSig.getGenericParams().back()->getDepth();
+  unsigned innerDepth = genericSig->getMaxDepth();
   if (!genericDecl->isGeneric())
     ++innerDepth;
 

tools/SourceKit/lib/SwiftLang/SwiftDocSupport.cpp

@@ -286,10 +286,7 @@ static void initDocGenericParams(const Decl *D, DocEntityInfo &Info,
         DC = D->getInnermostDeclContext()->getInnermostTypeContext();
       M = DC->getParentModule();
       SubMap = BaseType->getContextSubstitutionMap(M, DC);
-      if (!SubMap.empty()) {
-        TypeContextDepth = SubMap.getGenericSignature()
-            .getGenericParams().back()->getDepth() + 1;
-      }
+      TypeContextDepth = SubMap.getGenericSignature().getNextDepth();
     }
   }