[tickprocessor] Consider top of the stack as pc if it points to a code object.

Previously, we would only consider it if it pointed to a full-code JS function.
Thus we could miss both optimized functions and bytecode handlers if they
called frame-less code.

Review-Url: https://codereview.chromium.org/2822433002
Cr-Commit-Position: refs/heads/master@{#44640}

tools/tickprocessor.js

@@ -365,7 +365,7 @@ TickProcessor.prototype.processTick = function(pc,
     // Find out, if top of stack was pointing inside a JS function
     // meaning that we have encountered a frameless invocation.
     var funcEntry = this.profile_.findEntry(tos_or_external_callback);
-    if (!funcEntry || !funcEntry.isJSFunction || !funcEntry.isJSFunction()) {
+    if (!funcEntry) {
       tos_or_external_callback = 0;
     }
   }