Summary: minor assembler enhancements preparing for method handles
Reviewed-by: kvn

Summary: Use NULL_WORD in the places where intptr_t is expected due to incompatible types between intptr_t & int32_t
Reviewed-by: phh, coleenp, never

6787106: Hotspot 32 bit build fails on platforms having different definitions for intptr_t & int32_t
Summary: Avoid casting between int32_t and intptr_t specifically for MasmAssembler::movptr in 32 bit platforms.
Reviewed-by: jrose, kvn

Summary: Update for files that have been modified starting July 2008
Reviewed-by: ohair, tbell

6459804: Want client (c1) compiler for x86_64 (amd64) for faster start-up
Reviewed-by: kvn