There are a few function declarations at the end of debug.hpp that seem misplaced there. Some might be better placed in VMError. Some are test support, though perhaps VMError is still a good place for them. The functions in question are:

is_error_reported()
set_error_reported()
test_error_handler() -- NOT_PRODUCT
controlled_crash(int) -- NOT_PRODUCT
get_segfault_address() -- NOT_PRODUCT
pd_ps(frame)

Moving these elsewhere would leave debug.hpp as containing assert-like macros plus functions for reporting errors (some being in support of the macros).