Summary: ELFv2 ABI used by the little endian PowerPC64 on Linux.
Reviewed-by: kvn
Contributed-by: asmundak@google.com

Reviewed-by: kvn

Summary: Fixed Implicit NULL check optimization for AIX, where the page at address '0' is only write-protected.
Reviewed-by: kvn

Summary: Some platforms, as ppc and s390x/zArch require that 32-bit ints are passed as 64-bit values to C functions. This change adds support to adapt the signature and to issue proper casts to c2-compiled stubs. The functions are used in generate_native_wrapper(). Adapt signature used by the compiler as in PhaseIdealLoop::intrinsify_fill().
Reviewed-by: kvn

Summary: With this change the HotSpot core build works on Linux/PPC64. The VM succesfully executes simple test programs.
Reviewed-by: kvn