Vector3 Interop tests

Vector3 Interop tests

The native type of Vector3 is struct {float x,y,z} whose size is 12 bytes. RyuJit uses 16-byte register or stack location to store a Vector3 variable with the assumptions below. New testcases are added to check whether RyuJit properly handle interop cases.

RyuJIt back-end makes two assumptions about Vector3 types.

Assumption1: Vector3 type args passed in registers or on stack is rounded to POINTER_SIZE and hence on 64-bit targets it can be read/written as if it were TYP_SIMD16.

Assumption2: Vector3 args passed in registers (e.g. unix) or on stack have their upper 4-bytes being zero. Similarly Vector3 return type value returned from a method will have its upper 4-bytes zeroed out.