Correct OpSpecConstantOp generation (CTS basic/progvar_prog_scope_init)

[iliya-diyachkov]

Compiling OpenCL_CTS_2021/basic/progvar_prog_scope_init/OCL_asm8433e5f712585356_before_spirv_backend.ll which has this fragment

a_var = addrspace(1) global [2 x <2 x i8>] [<2 x i8> <i8 1, i8 1>, <2 x i8> <i8 1, i8 1>], align 2
@p_var = addrspace(1) global <2 x i8> addrspace(1)* bitcast (i8 addrspace(1)* getelementptr (i8, i8 addrspace(1)* getelementptr inbounds ([2 x <2 x i8>], [2 x <2 x i8>] addrspace(1)* @a_var, i32 0, i32 0, i32 0), i64 2) to <2 x i8> addrspace(1)*), align 8

I get following output:

        %23 = OpVariable %9 CrossWorkgroup %31
        %24 = OpVariable %10 CrossWorkgroup %17
        %25 = OpVariable %8 CrossWorkgroup %16
        %26 = OpVariable %8 CrossWorkgroup %29
        %30 = OpConstant %2 0 
        %29 = OpConstantComposite %3 %30 %30
        %31 = OpSpecConstantOp %10 70 %24 %18 %19
        %35 = OpConstant %2 0 
        %34 = OpConstantComposite %3 %35 %35
        %36 = OpSpecConstantOp %10 70 %24 %18 %19
        %41 = OpConstant %2 0 
        %40 = OpConstantComposite %3 %41 %41
        %42 = OpSpecConstantOp %10 70 %24 %18 %19
        %63 = OpConstant %2 0 
        %62 = OpConstantComposite %3 %63 %63
        %64 = OpSpecConstantOp %10 70 %24 %18 %19

The SPIRV translator gives this output:

          %8 = OpConstantComposite %v2uchar %uchar_1 %uchar_1
...
         %13 = OpConstantComposite %_arr_v2uchar_ulong_2 %8 %8
      %a_var = OpVariable %_ptr_CrossWorkgroup__arr_v2uchar_ulong_2 CrossWorkgroup %13
         %19 = OpSpecConstantOp %_ptr_CrossWorkgroup_uchar PtrAccessChain %a_var %uint_0 %uint_0 %ulong_2
         %20 = OpSpecConstantOp %_ptr_CrossWorkgroup_v2uchar Bitcast %19
      %p_var = OpVariable %_ptr_CrossWorkgroup__ptr_CrossWorkgroup_v2uchar CrossWorkgroup %20

So we need to correct OpSpecConstantOp generation and avoid the instruction duplication.