check-static-inits: check for static finalizers
check-static-inits: Filter out zero-length sections

When compiling with -O0, zero-sized constructors were showing up
and confusing the test.
Don't use tmp files in Makefile

Useful for code-coverage generation of the ragel-generated files
as they will now contain the correct .hh filename in them.
Clean ragel-generated headers in maintainercleanfiles
Create ragel-generated files in srcdir