spirv: Fix implicit lod type

src/shader_recompiler/backend/spirv/emit_context.h

@@ -101,6 +101,10 @@ public:
         return Constant(U32[1], value);
     }
 
+    Id Const(f32 value) {
+        return Constant(F32[1], value);
+    }
+
     Id Const(u32 element_1, u32 element_2) {
         return ConstantComposite(U32[2], Const(element_1), Const(element_2));
     }

src/shader_recompiler/backend/spirv/emit_spirv_image.cpp

@@ -320,7 +320,7 @@ Id EmitImageSampleImplicitLod(EmitContext& ctx, IR::Inst* inst, const IR::Value&
         // We can't use implicit lods on non-fragment stages on SPIR-V. Maxwell hardware behaves as
         // if the lod was explicitly zero.  This may change on Turing with implicit compute
         // derivatives
-        const Id lod{ctx.Const(0)};
+        const Id lod{ctx.Const(0.0f)};
         const ImageOperands operands(ctx, false, true, info.has_lod_clamp != 0, lod, offset);
         return Emit(&EmitContext::OpImageSparseSampleExplicitLod,
                     &EmitContext::OpImageSampleExplicitLod, ctx, inst, ctx.F32[4],