MSL: invalid code generated when atan2 and saturate are used in mixed precision environment

[BlurryLight]

the following hlsl generate invalid msl:
https://godbolt.org/z/7aM4j9Tnb
dxc args: -T ps_6_6 -E PSMain -spirv -enable-16bit-types

float4 PSMain(PSInput input) : SV_Target0
{
  return saturate(atan2(1.0h, 2.0h));
}

which generate invalid msl: https://shader-playground.timjones.io/ebece9aee93af143eb7801593f8cf51a

fragment PSMain_out PSMain()
{
    PSMain_out out = {};
    out.out_var_SV_Target0 = float4(float(clamp(precise::atan2(half(1.0), half(2.0)), half(0.0), half(1.0))));
    return out;
}

the error msg is "error: call to 'clamp' is ambiguous", because it tries to call a function clamp(float,half,half).

Potential cause

it seems spirv-cross always emits precise::atan2 instead of the relaxed precision version.

SPIRV-Cross/spirv_msl.cpp

Lines 10415 to 10416 in 0640756

	case GLSLstd450Atan2:
	emit_binary_func_op(result_type, id, args[0], args[1], "precise::atan2");

[HansKristian-Work]

Problem is that there is no half overload in MSL, even for fast:: variant. Trivial to workaround I suppose.