Revert "Disable shared library support when compiler links statically" (#15855)

In commit v3.4.0-rc1~18^2 (Disable shared library support when compiler
links statically, 2015-09-30) we tried to detect when the compiler is
not capable of linking shared libraries (possibly due to flags in use).
However, the approach is not robust against flags like `-nostdlib`.
Revert it for now pending another solution to the original problem.