X86Assembler - Minor fixes related to illegal instruction/illegal addressing error handling.
X86Compiler - Always create SArg for every stack-based function argument
X86Compiler - Possible to allocate a register that has to be used to convert variable to function argument.
X86Compiler - ContextID generation moved to context_p.h.
X86Compiler - Support for one variable being used by multiple function-call arguments.
X86Defs - Removed support for 'long double' (buggy, never used).
X86Func - Register arguments have to be converted from Fp32/Fp64 to XmmSs/XmmSd, respectively.