Add pre build task to detect if ADVAPI32.dll or GenRandom function will be included

[charlesportwoodii]

There needs to be a pre-build task to determine if compilation on ARM should proceed.. If any of the default randombytes implementation are even included GenRtlRandom usually ends up being included, resulting in runtime failures. Unfortunately Visual Studio can't detect this during compile time, resulting in a loss of time.

We can easily implement a pre-build check for this.

Additionally it would be worthwhile to add a post build task to AppVeyor and the project that checks dumpbin /dependents to see if ADVAPI32.dll is listed as a dependent for ARM, and to fail the build if it does.