[spirv-in] More sign-agnostic operations

[afd]

I did some more fuzzing with spirv-fuzz following the fixes in #1603, but it seems there are some more sign-agnostic ops that are not handled. Naga complains about these valid uses of OpBitwise{And, Or, Xor} and OpSNegate:

               OpCapability Shader
          %1 = OpExtInstImport "GLSL.std.450"
               OpMemoryModel Logical GLSL450
               OpEntryPoint Fragment %4 "main"
               OpExecutionMode %4 OriginUpperLeft
       %void = OpTypeVoid
          %3 = OpTypeFunction %void
       %uint = OpTypeInt 32 0
     %uint_1 = OpConstant %uint 1
        %int = OpTypeInt 32 1
      %int_0 = OpConstant %int 0
          %4 = OpFunction %void None %3
          %5 = OpLabel
        %583 = OpBitwiseAnd %uint %uint_1 %int_0
        %584 = OpBitwiseOr %uint %uint_1 %int_0
        %585 = OpBitwiseXor %uint %uint_1 %int_0
        %588 = OpSNegate %int %uint_1
               OpReturn
               OpFunctionEnd

Here is another example using OpSMod that gets rejected:

               OpCapability Shader
          %1 = OpExtInstImport "GLSL.std.450"
               OpMemoryModel Logical GLSL450
               OpEntryPoint Fragment %4 "main"
               OpExecutionMode %4 OriginUpperLeft
       %void = OpTypeVoid
          %3 = OpTypeFunction %void
        %int = OpTypeInt 32 1
      %int_0 = OpConstant %int 0
       %uint = OpTypeInt 32 0
    %uint_16 = OpConstant %uint 16
          %4 = OpFunction %void None %3
          %5 = OpLabel
         %98 = OpSMod %int %int_0 %uint_16
               OpReturn
               OpFunctionEnd

And an example using OpSDiv that gets rejected:

               OpCapability Shader
          %1 = OpExtInstImport "GLSL.std.450"
               OpMemoryModel Logical GLSL450
               OpEntryPoint Fragment %4 "main"
               OpExecutionMode %4 OriginUpperLeft
       %void = OpTypeVoid
          %3 = OpTypeFunction %void
       %uint = OpTypeInt 32 0
        %int = OpTypeInt 32 1
     %int_16 = OpConstant %int 16
    %uint_16 = OpConstant %uint 16
          %4 = OpFunction %void None %3
          %5 = OpLabel
         %20 = OpSDiv %int %int_16 %uint_16
               OpReturn
               OpFunctionEnd