- Generate a list of *.o -> lib*.{a,so} mapping.  This is also known by
  parsing dependency lines in libgcc.mk.

- Generate a list of *.o -> *.{c,S} mapping.  *.S files are known as
  ${LIB1ASMFUNCS}.  Assume other *.o files are built from *.c.  This information
  is needed to generated wrapper sources later.

(uebayasi)