[SPIR-V] Fatal error instead of ordinary error with file and line number when `SV_IsFrontFace` is not bool.

Description
When entry point parameter with SV_IsFrontFace semantic have type other than bool, SPIR-V compilation result in fatal error:

fatal error: generated SPIR-V is invalid: [VUID-FrontFacing-FrontFacing-04231] According to the Vulkan spec BuiltIn FrontFacing variable needs to be a bool scalar. ID <2> (OpVariable) is not a bool scalar.
  %gl_FrontFacing = OpVariable %_ptr_Input_uint Input

note: please file a bug report on https://github.com/Microsoft/DirectXShaderCompiler/issues with source code if possible

Steps to Reproduce
https://godbolt.org/z/1v7ec17nG

Compile with -E PSMain -T ps_6_6 -spirv

struct VSOut
{
	float3 pos : SV_Position;
};

float4 PSMain(
    VSOut input,
    uint isFrontFace : SV_IsFrontFace) : SV_Target
{
	return (isFrontFace ? 1.0 : -1.0);
}

Actual Behavior
Ordinary error with file and line number should be displayed instead of fatal error.

Environment

• DXC version: 1.8 - 1.8.0.4666 (release-1.8.2407, 8df0a9d2e)
• Host Operating System: Windows 11 23H2

Start with the HLSL reproducer from the Godbolt link and run it with -E PSMain -T ps_6_6 -spirv. Trace how the generated SPIR-V validation failure is reported and preserve the requested source file and line information. Done means this invalid SV_IsFrontFace type produces an ordinary compiler error instead of a fatal error.