[Type checker] Fix DeclContext computation for inherited type lookup.

Author: DougGregor

lib/Sema/TypeCheckDecl.cpp

@@ -248,20 +248,6 @@ void TypeChecker::checkInheritanceClause(Decl *decl,
   } else if (auto ext = dyn_cast<ExtensionDecl>(decl)) {
     DC = ext;
     options |= TypeResolutionFlags::AllowUnavailableProtocol;
-  } else if (isa<GenericTypeParamDecl>(decl)) {
-    // For generic parameters, we want name lookup to look at just the
-    // signature of the enclosing entity.
-    DC = decl->getDeclContext();
-    if (auto nominal = dyn_cast<NominalTypeDecl>(DC)) {
-      DC = nominal;
-    } else if (auto ext = dyn_cast<ExtensionDecl>(DC)) {
-      DC = ext;
-    } else if (auto func = dyn_cast<AbstractFunctionDecl>(DC)) {
-      DC = func;
-    } else if (!DC->isModuleScopeContext()) {
-      // Skip the generic parameter's context entirely.
-      DC = DC->getParent();
-    }
   } else {
     DC = decl->getDeclContext();
   }

lib/Sema/TypeCheckRequestFunctions.cpp

@@ -33,21 +33,6 @@ Type InheritedTypeRequest::evaluate(
       options |= TypeResolutionFlags::AllowUnavailableProtocol;
     } else {
       dc = typeDecl->getDeclContext();
-
-      if (isa<GenericTypeParamDecl>(typeDecl)) {
-        // For generic parameters, we want name lookup to look at just the
-        // signature of the enclosing entity.
-        if (auto nominal = dyn_cast<NominalTypeDecl>(dc)) {
-          dc = nominal;
-        } else if (auto ext = dyn_cast<ExtensionDecl>(dc)) {
-          dc = ext;
-        } else if (auto func = dyn_cast<AbstractFunctionDecl>(dc)) {
-          dc = func;
-        } else if (!dc->isModuleScopeContext()) {
-          // Skip the generic parameter's context entirely.
-          dc = dc->getParent();
-        }
-      }
     }
   } else {
     auto ext = decl.get<ExtensionDecl *>();