fix: term macro errors should be fatal

src/Lean/Elab/Term.lean

@@ -1216,7 +1216,8 @@ private partial def elabTermAux (expectedType? : Option Expr) (catchExPostpone :
     withNestedTraces do
     let env ← getEnv
     match (← liftMacroM (expandMacroImpl? env stx)) with
-    | some (decl, Except.ok stxNew) =>
+    | some (decl, stxNew?) =>
+      let stxNew ← liftMacroM <| liftExcept stxNew?
       withInfoContext' (mkInfo := mkTermInfo decl (expectedType? := expectedType?) stx) <|
         withMacroExpansion stx stxNew <|
           withRef stxNew <|

tests/lean/macroError.lean

@@ -0,0 +1,3 @@
+macro "foo" : term => Lean.Macro.throwError "Test Error"
+
+#check foo

tests/lean/macroError.lean.expected.out

@@ -0,0 +1 @@
+macroError.lean:3:7-3:10: error: Test Error