* libc/machine/powerpc/fix64.h: Fix typo for _simdldcheck
prototype.
* libc/machine/powerpc/simdldtoa.c: Remove prototype for
_simdldcheck(). Also add unsigned cast for index variable in
for loop using sizeof operators.
* libc/machine/powerpc/strtoufix32.c: Remove unused variable.
* libc/machine/powerpc/strtosfix64.c: Fix call to _simdldcheck.
* libc/machine/powerpc/strtoufix64.c (_strtoufix64_r): Ditto
plus fix shift calculation for determining if there is a
carry from word2.