The patch to the linker does this when generating the pclntab,
which is the binary section containing func names.
When `-tiny` is being used, we look for unexported funcs,
and set their names to the offset `0` - a shared empty string.
We also avoid including the original name in the binary,
which saves a significant amount of space.
The following stats were collected on GOOS=linux,
which show that `-tiny` is now about 4% smaller:
go build 1203067
garble build 782336
(old) garble -tiny build 688128
(new) garble -tiny build 659456
pagran