Merge elftoolchain r3877 (by jkoshy):

Merge elftoolchain r3877 (by jkoshy):

  Incorporate fixes from Dimitry Andric:

  - Use a BUFFER_GROW() macro to avoid rounding errors in capacity
    calculations.
  - Fix a bug introduced in [r3531].
  - Fix handling of nested template parameters.

  Ticket:	#581

This should fix a number of assertions on elftoolchain's cxxfilt, and
allow it to correctly demangle several names that it could not handle
before.

Obtained from:	https://sourceforge.net/p/elftoolchain/code/3877/
PR:		250702
MFC after:	3 days