support PIE executables?

[Ralf Wildenhues]

Would it be worthwhile for Libtool to support building
position-independent executables (PIE) on platforms that support it?

With the surge of security-related features that use PIE, and all the
knowledge Libtool already has integrated, this should be fairly
painless and might prove helpful, I think.

Are there many non-GNU systems that allow this?  Even if not, the
fallback to normal executables is usually an acceptable graceful
degradation.

What do you think?  Add it to TODO?

Regards,
Ralf