add test for asint

[spall]

Adds a test for asint testing int, uint, and float types.
Closes #169

[Icohedron]

This doesn't seem correct to me. Shouldn't it be the following?

Suggested change

	Data: [-1, 0, -2147483648, 2147483647, -1, 0, -2147483648, 2147483647, -1, 0, 0, 0]
	Data: [-4194304, 0, -2147483648, 2143289344, -4194304, 0, -2147483648, 2143289344, -4194304, 0, 0, 0]

Because Out3 should be:

[asint(-nan), asint(0), asint(-0), asint(nan), asint(-nan), asint(0), asint(-0), asint(nan), asint(-nan), asint(0), 0, 0]

which should be the same as interpreting these hex values as int32s

[0xffc00000, 0x0, 0x80000000, 0x7fc00000, 0xffc00000, 0x0, 0x80000000, 0x7fc00000, 0xffc00000, 0x0, 0x0, 0x0]