This is a big change that will determine the stack size for many
goroutines automatically. Functions that aren't recursive and don't call
function pointers can in many cases have an automatically determined
worst case stack size. This is useful, as the stack size is usually much
lower than the previous hardcoded default of 1024 bytes: somewhere
around 200-500 bytes is common.
A side effect of this change is that the default stack sizes (including
the stack size for other architectures such as AVR) can now be changed
in the config JSON file, making it tunable per application.
The name was cortex-m.s which looks like it is a generic assembly file
for all cortex-m targets. However, it really is only for qemu
simulation, because every chip has a slightly different interrupt vector
table.
Ayke van Laethem