V3 PATCH: numeric_limits<> support, fix PR/3865

[Gabriel Dos Reis]

Graham Stott <graham.stott@btinternet.com> writes:

| This patch causes problems building x86 cross v850-elf, and arm-elf toolchains
| which both fail with
| 
| /usr/local/src/uberbaum/libstdc++-v3/src/limits.cc:56: error: excess elements
|     in aggregate initializer
| /usr/local/src/uberbaum/libstdc++-v3/src/limits.cc:58: error: excess elements
|     in aggregate initializer
| /usr/local/src/uberbaum/libstdc++-v3/src/limits.cc:60: error: excess elements
|     in aggregate initializer
| /usr/local/src/uberbaum/libstdc++-v3/src/limits.cc:62: error: excess elements
|     in aggregate initializer

This means that something is wrong with the long double size in byte
and in bits.  Please could you tell me what they should be and what
are their current values?  Thanks.

-- Gaby