6587322: dtrace probe object__alloc doesn't fire in some situations on amd64

Summary: Fix misplaced probe point
Reviewed-by: rasbold, phh
Contributed-by: neojia@gmail.com

src/cpu/x86/vm/templateTable_x86_64.cpp

@@ -3238,17 +3238,19 @@ void TemplateTable::_new() {
     __ xorl(rcx, rcx); // use zero reg to clear memory (shorter code)
     __ store_klass_gap(rax, rcx);  // zero klass gap for compressed oops
     __ store_klass(rax, rsi);      // store klass last
+
+    {
+      SkipIfEqual skip(_masm, &DTraceAllocProbes, false);
+      // Trigger dtrace event for fastpath
+      __ push(atos); // save the return value
+      __ call_VM_leaf(
+           CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc), rax);
+      __ pop(atos); // restore the return value
+
+    }
     __ jmp(done);
   }
 
-  {
-    SkipIfEqual skip(_masm, &DTraceAllocProbes, false);
-    // Trigger dtrace event for fastpath
-    __ push(atos); // save the return value
-    __ call_VM_leaf(
-         CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc), rax);
-    __ pop(atos); // restore the return value
-  }
 
   // slow case
   __ bind(slow_case);