Use GeneratedDllImport in System.Security.Cryptography.Encoding

[elinor-fung]

	Original (B)	Converted (B)	+ (B)	+ (%)
linux	43008	47104	4096	9.52
windows	40448	41472	1024	2.53
linux R2R	91136	104448	13312	14.61
windows R2R	83456	86016	2560	3.07

cc @AaronRobinsonMSFT @jkoritzinsky

[jkotas]

This cal call ErrGetErrorAlloc just once to make the code smaller:

ulong error = 0;
bool isAllocFailure = false;
while (true)
{
    ulong lastRead = ErrGetErrorAlloc(&lastIsAllocFailure);

    // 0 (there's no named constant) is only returned when the calls
    // to ERR_get_error exceed the calls to ERR_set_error.
    if (lastRead == 0)
        break;

    error = lastRead;
    isAllocFailure = lastIsAllocFailure;
}

[jkotas]

14.61

Do you have a sense where it is mostly comming from? Is it string marshaling or the SafeHandles, or something else?

[elinor-fung]

I suspect it is from string marshalling, followed by safe handles.

I'm not actually sure what the best way would be to determine the breakdown. I had just done an r2rdump --diff between the two binaries and saw the functions marshalling strings and safe handles were at the top, then just strings, and just safe handles.