AST: Remove assertion in typo correction

CSDiag can try doing lookups on unbound generic types, so just remove this
assertion.

Author: slavapestov

lib/AST/LookupVisibleDecls.cpp

@@ -847,10 +847,6 @@ class OverrideFilteringConsumer : public VisibleDeclConsumer {
 
     // Does it make sense to substitute types?
 
-    // Don't pass UnboundGenericType here. If you see this assertion
-    // being hit, fix the caller, don't remove it.
-    assert(IsTypeLookup || !BaseTy->hasUnboundGenericType());
-
     // If the base type is AnyObject, we might be doing a dynamic
     // lookup, so the base type won't match the type of the member's
     // context type.

test/Sema/typo_correction.swift

@@ -112,6 +112,16 @@ struct Generic<T> {
   }
 }
 
+protocol P { // expected-note {{'P' previously declared here}}
+  typealias a = Generic
+}
+
+protocol P {} // expected-error {{invalid redeclaration of 'P'}}
+
+func hasTypo() {
+  _ = P.a.a // expected-error {{value of type 'Generic' has no member 'a'}}
+}
+
 // Typo correction with AnyObject.
 func takesAnyObject(_ t: AnyObject) {
   _ = t.rawPointer

validation-test/compiler_crashers/28814-basety-hasunboundgenerictype.swift renamed to validation-test/compiler_crashers_fixed/28814-basety-hasunboundgenerictype.swift

@@ -5,6 +5,6 @@
 // See https://swift.org/LICENSE.txt for license information
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
-// REQUIRES: asserts
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+
+// RUN: not %target-swift-frontend %s -emit-ir
 protocol P{typealias a=FlattenCollection}{{P.a.a}}protocol P