[wgsl-in] Numeric suffixes + unsanitised related error

[hanawatson]

Hi - I noticed that naga doesn't seem to correctly parse numeric suffixes (except for u for unsigned integers u32). According to the spec, WGSL theoretically also allows i (i32), f (f32) and h (f16, although f16 support/extension seems to be very new to the spec).

code example (analogous behavior for the i suffix and the f without exponent):

@stage(compute) @workgroup_size(1)
fn compute_main(
) {
	var var0: f32 = -2.9007446E38f;
}

resultant error:

error: expected ';', found 'f'
  ┌─ test.wgsl:6:31
  │
6 │     var var0: f32 = -2.9007446E38f;
  │                                  ^ expected ';'

Could not parse WGSL

Also (sorry to bombard you with issues!) - while checking the special 0x1f case just above this section of the spec https://gpuweb.github.io/gpuweb/wgsl/#keywords, I got an error that I suspect might not have been meant to be user-exposed.

code:

@stage(compute) @workgroup_size(1)
fn compute_main(
) {
	var var0: f32 = 0x1f;
}

error:

[2022-04-16T19:02:13Z ERROR naga::front::wgsl] Given type Scalar { kind: Float, width: 4 } doesn't match expected Scalar { kind: Sint, width: 4 }
error: the type of `var0` is expected to be `i32`
  ┌─ test1.wgsl:4:6
  │
4 │     var var0: f32 = 0x1f;
  │         ^^^^ definition of `var0`

Could not parse WGSL