- added portasm support for adding .section .note.GNU-stack "hints" marking generated .o files from assembly files as not needing an executable stack * needed to be done manually in assembly files, in contrast to C translation units where gcc adds such hints automatically * this is for security, and better/easier integration of dyncall into other projects and builds, as dyncall doesn't need an executable stack * thanks to Thorsten Behrens for bringing this up to our intention and providing a first analysis * currently only done on Linux, but will be added across other platforms (where applicable) after some testing

- implement structure passing for all calling conventinos and platforms
- make sure that struct support for ellipsis calls are not forgotten (copy everything by value)

- merge arm32_thumb_{gas/apple} and include thumb support for portasm
- check dyncall_call_x64_traditional_cpp.S / try-sync with win64 masm
- remove dyncall_call_x86_apple.s
- x64 port cleanup: all x64 calling conventions on all platforms
- remove dyncall_call_x86_masm.asm dyncall_call_x64_masm.asm
- x64 verification: return values are passed via RAX and RDX, and XMM0 and XMM1.