Add OSX@PowerPC support to UNO/C++ bridge

It is the same as Linux@PowerPC 32-bit (cp -r gcc3_linux_powerpc gcc3_macosx_powerpc),
with differences applied:
      * Use 13 FP registers and correct 'codeSnippetSize' (8*4 + 13*8 = 136).
      * Use "frame pointer + 24", not "+8".
      * Don't USE_DOUBLE_MMAP and 'sal_PtrDiff writetoexecdiff'.
      * Don't use "__NO_FPRS__", OS X capable PowerPC machines all have FPRs.
      * Use "rN"/"fN" syntax to avoid "Parameter syntax error" errors.
      * Include sys/types.h, sys/malloc.h instead of malloc.h;
        don't include string.h.

Change-Id: I5b251c65466af2a06bd309d3a7b1aaf26ac12656
Reviewed-on: https://gerrit.libreoffice.org/7072
Reviewed-by: Norbert Thiebaud <nthiebaud@gmail.com>
Tested-by: Norbert Thiebaud <nthiebaud@gmail.com>