Examine the Suffix hint on integers to apply apropriate TyTy type.

[philberty]

This change propagates the PrimitiveCoreType to AST and HIR so the suffix can be examined.

fn main() {
    let a1: i8 = 1i8;
    let a2: i16 = 2i16;
    let a3: i32 = 3i32;
    let a4: i64 = 4i64;
    let a5: i128 = 5i128;

    let b1 = 1i8;
    let b2 = 2i16;
    let b3 = 3i32;
    let b4 = 4i64;
    let b5 = 5i128;

    let c1: u8 = 1u8;
    let c2: u16 = 2u16;
    let c3: u32 = 3u32;
    let c4: u64 = 4u64;
    let c5: u128 = 5u128;

    let d1 = 1u8;
    let d2 = 2u16;
    let d3 = 3u32;
    let d4 = 4u64;
    let d5 = 5u128;
}

void main ()
{
  i8 a1;
  i16 a2;
  i32 a3;
  i64 a4;
  i128 a5;
  i8 b1;
  i16 b2;
  i32 b3;
  i64 b4;
  i128 b5;
  i8 c1;
  i16 c2;
  i32 c3;
  u64 c4;
  u128 c5;
  i8 d1;
  i16 d2;
  i32 d3;
  u64 d4;
  u128 d5;

  a1 = 1;
  a2 = 2;
  a3 = 3;
  a4 = 4;
  a5 = 5;
  b1 = 1;
  b2 = 2;
  b3 = 3;
  b4 = 4;
  b5 = 5;
  c1 = 1;
  c2 = 2;
  c3 = 3;
  c4 = 4;
  c5 = 5;
  d1 = 1;
  d2 = 2;
  d3 = 3;
  d4 = 4;
  d5 = 5;
}

[SimplyTheOther]

PR looks great.