Fix unsafe examples

[nxtn]

Fixes dotnet/docs#11067

int -> IntPtr for HANDLE
int -> UIntPtr for SIZE_T

BTW the coding styles in this repo are terrible.

/cc @Thraka @BillWagner

[nxtn]

@BillWagner Can you review this?

[mairaw]

@gafter @jcouv would you be the right people to review this?

[BillWagner]

@mairaw

I've got primary responsibility on these now. I'll pull in others if needed for further review.

[BillWagner]

Thanks for making these updates @NextTurn We appreciate it.

I've reviewed everything, and I'll approve this. I'm checking with others before we merge this though.

We 're working with ECMA to update the standard. The version published here needs to be reconciled with the 5.0 standard. We want to avoid further divergence between those two versions. The sections updated in this PR are not present in the ECMA 5.0 standard. For that reason, I believe this should be merged: It won't increase the committee's work reconciling the versions. It will decrease work validating new content, because this PR does fix errors in the code sample.

/cc @gafter @MadsTorgersen