[WebGPU] Crash in ConstantValue::integerValue() because the activeType is float

[Mike Wyrzykowski]

The following WGSL source generates a crash in ConstantValue::integerValue() because the activeType is float:

override x: u32 = 1u;
override y: u32 = 1u;
override z: u32 = 1u;
@compute @workgroup_size(x, y, z) fn main () {
  _ = 0u;
}

Generated Metal code:
#include <metal_stdlib>
#include <metal_types>

using namespace metal;

constant unsigned global0 [[function_constant(0)]];
constant unsigned global1 [[function_constant(1)]];
constant unsigned global2 [[function_constant(2)]];
[[kernel]]  void function0()
{
    (void)(0u);
}

[Radar WebKit Bug Importer]

<rdar://problem/119206116>

[Mike Wyrzykowski]

Pull request: https://github.com/WebKit/WebKit/pull/21350

[EWS]

Committed 271743@main (81a7c89e229f): <https://commits.webkit.org/271743@main>

Reviewed commits have been landed. Closing PR #21350 and removing active labels.