remove warning about missing 'const' support from docs and fix advice on declaring macros as 'enum' (which works only for ints)

Fix overflow_check CompileError with msvc

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extra : transplant_source : %3FH%B6t%1FFL%D8%2BF%7CV%7D%10T9%EA%CB%A0%00

enable control flow analysis for stack allocated structured variables (struct, union, array, C++ class)

rewrite except-as semantics using try-finally - seems to be the easiest way to get flow control analysis working for all cases

Add test for memoryview of extension type

Fix calling an "except +" cpp function in a nogil function

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extra : transplant_source : %8A%F1%17%5C%A7%CA%1C%B1%17%A1%C5t%06O%5BI%F2%19Vq