[BOLT] Increase BufSize in runtime/common.h (#204607)
During my work towards bolring the flang binary, I've encountered a
frequently occuring problem with running out of the buffer space.
The problem affects C++ programs with a decent number of very long
symbol names, which is inevitable when using template metaprogramming.
As one can clearly see, flang is one of such programs.
The proposed BufSize value is an effect of the trial-and-error process
aiming at finiding the smallest reasonable increase.
