grsecurity: Teardown of a Failed Linux LTS Spectre Fix

From gcc(1): "Warn when a declaration is found after a statement in a block. This construct, known from C++, was introduced with ISO C99 and is by default allowed in GCC. It is not supported by ISO C90."

So old C versions required all declarations to appear first in a block. C++ removed that requirement and the ISO standards committee backported that relaxation of the rules to C99.