The fp code relies on C99, and depending on gcc version, the default
is to use c89. This patch adds -std=c99 when using gcc to ensure the
code is compiled in ISO C99 mode.
This changeset includes libfputils from revision bbf0d61d75. This
library can be used to convert to and from 80-bit floats and query the
type of an 80-bit float, which is needed to support the x87 FPU.