configury: make systemtap buildable with gcc -flto

configury: make systemtap buildable with gcc -flto

Two problems corrected:

1 - Some of the stap object files compiled the interned_string type
    differently based on whether config.h was #included early enough
    or not.  Now they all do it at the top.

2 - The staprun/libstrfloctime.a pseudo-archive (added in commit
    0a5f4aa83e5b4 to work around an autoconf limitation), needs a
    -Wl,--whole-archive wrapper around it for lto linking purposes.

Now also stap builds on f32 both with and without:

  make CXX="g++ -flto" CC="gcc -flto"