Fix various intrinsic signatures around dynamic and open arrays

[cirras]

This PR fixes several intrinsic signatures to handle array size types properly.
It's a symmetrical change with #312.

Due to the current asymmetry, it's very trivial to get PlatformDependentTruncation false-positives with cases like:

procedure Test(Foo: TArray<Byte>; Bar: TArray<Byte>);
begin
  // Length returns NativeInt, and SetLength incorrectly expects Integer.
  SetLength(Foo, Length(Bar));
end;

[fourls]

Change looks good. Just to confirm my understanding, passing an Int64 to these intrinsics should now cause a PlatformDependentTruncation issue? Assuming the Delphi documentation is correct (...), this is the right behaviour.

[cirras]

Change looks good. Just to confirm my understanding, passing an Int64 to these intrinsics should now cause a PlatformDependentTruncation issue? Assuming the Delphi documentation is correct (...), this is the right behaviour.

No - and it's kind of an irritating problem.
For accuracy reasons, we return Integer for array sizes on 32-bit. We'd need custom handling in the PlatformDependent* rules to consistently detect this on 32-bit toolchains. On 64-bit toolchains, it will work as expected.

In summary - false negatives on 32-bit.