Infer correct type from numeric literals.

[iwoplaza]

• Create an AbstractInt type symbol (similar to UnknownData) that signifies the type is some integer, but we cannot be sure whether it is an u32 or i32.
• Create an AbstractFloat type symbol (similar to UnknownData) that signifies the type is some float, but we cannot be sure whether it is an f32 or f16.
• Infer the type of a literal numeric string based on its format ('u' suffix -> U32, 'i' suffix -> I32, . -> AbstractFloat, 'f' suffix -> F32, 'h' suffix -> F16, etc.)