[REG 4.1->4.2] Debugger is slow

Compared to 4.1, the debugger is extremely slow (about 3-4 times slower!).

I attached logs starting from the breakpoint.

What I did was only expanding some members.

Look at the tResponse time lines for fetchVariables.

4.1:

0.86 s
0.843 s
0.702 s
0.718 s

4.2:

0.468 s
2.183 s
2.514 s
2.527 s