ASTScope: Fix AttachedPropertyWrapperScope source range

The source range needs to contain the argument expression.

Author: slavapestov

include/swift/AST/ASTScope.h

@@ -966,19 +966,8 @@ class AttachedPropertyWrapperScope final : public ASTScopeImpl {
   CustomAttr *attr;
   VarDecl *decl;
 
-  /// Because we have to avoid request cycles, we approximate the test for an
-  /// AttachedPropertyWrapper with one based on source location. We might get
-  /// false positives, that that doesn't hurt anything. However, the result of
-  /// the conservative source range computation doesn't seem to be stable. So
-  /// keep the original here, and use it for source range queries.
-  const SourceRange sourceRangeWhenCreated;
-
   AttachedPropertyWrapperScope(CustomAttr *attr, VarDecl *decl)
-      : attr(attr), decl(decl),
-        sourceRangeWhenCreated(attr->getTypeRepr()->getSourceRange()) {
-    ASTScopeAssert(sourceRangeWhenCreated.isValid(),
-                   "VarDecls must have ranges to be looked-up");
-  }
+      : attr(attr), decl(decl) {}
   virtual ~AttachedPropertyWrapperScope() {}
 
 protected:

lib/AST/ASTScopeSourceRange.cpp

@@ -448,7 +448,7 @@ SourceRange ClosureParametersScope::getSourceRangeOfThisASTNode(
 
 SourceRange AttachedPropertyWrapperScope::getSourceRangeOfThisASTNode(
     const bool omitAssertions) const {
-  return sourceRangeWhenCreated;
+  return attr->getRange();
 }
 
 SourceRange GuardStmtScope::getSourceRangeOfThisASTNode(