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Later versions of the toolchain move on from the CFront model for static
object construction and destruction (which used symbols called '__link'
in object files which the linker manipulated into a linked list pointed at
by the symbol '__head').

Now, global or file-scope constructors are indicated by function pointers
emitted into the area C$$ctorvec, with the function bodies being emitted
into the area C$$ctor.

The C library supports the calling of global or file-scope destructors in
two ways: either they can be registered using atexit() calls from within the
corresponding constructor (these are issued first) or function pointers can
be provided in the area C$$dtorvec (with function bodies in the area
C$$dtor).

Function- or block-scope static-storage-duration destructors are a bit more
complicated, since they are only constructed when the block in which they
are declared comes into scope at run-time. For a module client, this means
that ...