Speed up gdb loading

[Ralf Habacker]

Hi Ebuka,

I remembered you mentioning the long loading time of gdb when debug
symbols are installed.

While working on another problem, I noticed that there is an environment
setting in Windows to disable heap debugging
https://ofekshilon.com/2014/09/20/accelerating-debug-runs-part-1-_no_debug_heap-2/
which can speed up load times.

c:\> set _NO_DEBUG_HEAP=1
c:\> gdb


Regards
Ralf