use sized types

protect against multiple inclusion

Commit SoC long double support from Stathis Kamperis

Merge the int bit with the high fraction bit. Add constants/macros
needed by gdtoa.

Push back the descriptions of NaN formats, and descriptions of the
distinction between signalling NaNs and quiet NaNs back into the
machine-dependent headers; treat the implementation of __nanf in th

Push back the descriptions of NaN formats, and descriptions of the
distinction between signalling NaNs and quiet NaNs back into the
machine-dependent headers; treat the implementation of __nanf in the
same spirit.

IEEE 754 leaves the distinction between signalling NaNs and quiet NANs
to the implementation, and unlike our headers used to suggest they're
not identical in the interpretation of the fraction's MSb; in due
course, make those of hppa, mips, sh3, and sh5 reflect reality.

show more ...

Err, rename some members added in previous to make them reflect their
semantics better.

For convenient use in libc, add unions of the C floating types and their
corresponding structure definitions.

Correct the position of the QUIETNAN bit.

Use <sys/ieee754.h> where applicable.

Reflect the explicit integer bit here as well.

Make ieee_ext match reality, and add a note about its ABI-specific
tail padding.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22364, verified by myself.

Move some files out of i386 into x86, so that they can be shared with
other ports.