the loop that invokes the static constructors. That makes it safe
to link c++rt0.o into any shared library, even one that does not
have any static constructors. Formerly, doing that would cause a
bus error. If the library has no static constructors, __CTOR_LIST__
comes out as a simple 4-byte COMMON region, and it does not have
the usual NULL word that terminates the list of constructors. This
caused the old code to "call" a garbage address via the non-existent
entry __CTOR_LIST__[1].
The analogous code that invokes the static destructors was already safe.
This change is fully backward-compatible.
Reviewed by: dfr@render.com (Doug Rabson)
83a650d90c