* rs6000/aix43.h (SUBTARGET_OVERRIDE_OPTIONS): Change non-PowerPC
        and AIX64 combination to warning.  Add warning for disabling
        PowerPC64 support when using 64-bit mode.
        (LIB_SPEC): Do not link with libg.a in 64-bit mode.
        (LINK_SPEC): Do not export libg.exp symbols in 64-bit mode.
        * rs6000/rs6000.h (MY_ISCOFF): Treat import/export files as valid
        XCOFF files.
        (read_only_data_section, private_data_section,
        read_only_private_data_section): Always align CSECTs to doubleword
        boundary regardless of mode.
        (TEXT_SECTION_ASM_OP): Align text CSECT on doubleword boundary in
        64-bit mode.
        (DATA_SECTION_ASM_OP): Always align CSECT to doubleword boundary.
        (ASM_OUTPUT_LOCAL): Use rounded size in 64-bit mode to
        maintain doublword alignment.

From-SVN: r26762