chore(tests): add Leo's test case for errors in solve1-blocks

tests/lean/auto_quote_error2.lean

@@ -45,3 +45,11 @@ begin
    { subst h1 },
             --^ error should be at `}`
 end
+
+example : true :=
+begin
+  {
+    note h' := eq.refl _,
+            --^  error should be on this line
+   }
+end

tests/lean/auto_quote_error2.lean.expected.out

@@ -42,3 +42,8 @@ state:
 b : ℕ,
 h2 : b = 0
 ⊢ 0 = b
+auto_quote_error2.lean:52:15: error: don't know how to synthesize placeholder
+context:
+⊢ Sort ?
+state:
+⊢ true