[inspector] changed a way of preserving stepping between tasks

test/inspector/debugger/step-into-expected.txt

 Checks possible break locations.
 
 Running test: testEval
 break at:
 function testEval() {
   #eval('// comment only');
   eval('// comment only\n');
 
 break at:
 // comment onl#y
@@ skipping 898 matching lines @@
       setTimeout(resolveNested, 0);
       await #p;
     }
 
 break at:
       setTimeout(resolveNested, 0);
       #await p;
     }
 
 break at:
-function return42() {
-  #return 42;
-}
-
-break at:
-  return 42;
-#}
-
-
-break at:
-  async function main() {
-    async function foo#() {
-      var resolveNested;
-
-break at:
       var resolveNested;
       var p = #new Promise(resolve => resolveNested = resolve);
       setTimeout(resolveNested, 0);
 
 break at:
       var resolveNested;
       var p = new Promise(resolve => resolveNested #= resolve);
       setTimeout(resolveNested, 0);
 
 break at:
@@ skipping 136 matching lines @@
 break at:
     async function foo() {
       await Promise.#resolve();
       return 42;
 
 break at:
     async function foo() {
       #await Promise.resolve();
       return 42;