libdfp: Fix decNumberLocal.h endian changes
libdfp: Fix test-bfp-convertion tests

So test-bfp-convertion convertions assumes that float/double/long double
holds precised values (for instance 12.345) in base 10, where in fact if
the variable is expanded to a more precision value (using prinft or a
multiprecion library) it will hold an different value
(12.345000267028809 in the 12.345 case for float). This patch fixes the
expected value to decimal transformation.
Refactor generic isnand
libdfp: isinfd refactor
libdfp: isfinite refactor
libdfp: Add llogb[32|64|128] implementation

Also adds [i|l]logb[32|64|128] testcases.
libdfp: Cleanup _IEEE_LIBDFP and _IEEE_LIBM
libdfp: Add rounding function tests

This patch adds tests for ceil, floor, nearbyint, round, and trunc
functions for _Decimal[32|64|128].
PowerPC: Optimized ceild[32|64|128]
PowerPC: Optimized truncd[32|64|128]
PowerPC: Optimized floord[32|64|128]
PowerPC: optimized nearbyintd[32|64|128]
PowerPC: optimized roundd[32|64|128]
libdfp: Add roundevend[32|64|128] implementation

This patch adds a software implementation for roundeven for
_Decimal[32|64|128]. The function rounds its argument to the
nearest integer value in floating-point format, rounding
halfway cases to even (that is, to the nearest value whose
least significant bit 0), regardless of the current rounding
direction
PowerPC: optimized roundevend[32|64|128]