Make various object discovery functions more tolerant of failure.
Small cleanups. Support output of symbol start addr in nearest_preceding_symbol.
Various fixes.
Minor fixes and debugging.
Fixes and extra debugging.
Yet more fixes to heap and memory kind logic.
discover: support getting allocating CU for an obj. A bit of refactoring.
Minor fixes.
Use std::shared_ptr. Consistently guard use of startup_brk on relevant preprocessor macro.
Comment Makefile to document old/new malloc hooks builds.
Comment Makefile to document old/new malloc hooks builds.
addrmap: account for maximum stack size, and add MAPPED_FILE memory classification as required by libcrunch.