Update the asm code in context2.S
hard coded the memory offset with an assumption that we are using standrad form

Seems the logic in context2.S is for custom stack, we may not need to follow the standard XSAVE buffer layout. Directly adding the APX section after AVX512.

Updates in threadsuspend.cpp

script-gen changes

Extending CPUID flag from int to long to hold more ISAs.

Update the cpuid check logic, make sure CR4.OSXSAVE and XCR0.APX_F are checked.

resolve comments

improve the logics in isa_detection in gc.

add missing method definitions under unix context.

code clean up

2. merge Avx512F, BW, CD, DQ to a converged ISA flag, Avx512.
3. introduce APX cpuid detection.