Fix up Ruby 2.7 pattern matching usage

Author: kddnewton

.rubocop.yml

@@ -78,3 +78,6 @@ Style/PerlBackrefs:
 
 Style/SpecialGlobalVars:
   Enabled: false
+
+Style/StructInheritance:
+  Enabled: false

lib/syntax_tree/language_server/inlay_hints.rb

@@ -73,8 +73,10 @@ def visit_binary(node)
       #     a ? b : ₍c ? d : e₎
       #
       def visit_if_op(node)
-        if stack[-2] in Assign | Binary | IfOp | OpAssign
+        case stack[-2]
+        in Assign | Binary | IfOp | OpAssign
           parentheses(node.location)
+        else
         end
 
         super

test/location_test.rb

@@ -15,15 +15,17 @@ def test_deconstruct
       location = Location.fixed(line: 1, char: 0, column: 0)
 
       case location
-      in [1, 0, 0, *]
+      in [start_line, 0, 0, *]
+        assert_equal(1, start_line)
       end
     end
 
     def test_deconstruct_keys
       location = Location.fixed(line: 1, char: 0, column: 0)
 
       case location
-      in start_line: 1
+      in start_line:
+        assert_equal(1, start_line)
       end
     end
   end