spirv: Use generic transform to process shader IO

The refactored CanonicalizeEntryPointIO transform makes it much easier
to handle SPIR-V style IO as well, and doing this removes a lot of
duplicated code. Remove all of the SPIR-V transform code for shader IO
and vertex point size.

Bug: tint:920
Change-Id: Id1b97517619b4d2fd09b45d5aee848259f3dfa77
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/60840
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: James Price <jrprice@google.com>
Auto-Submit: James Price <jrprice@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>

test/buffer/uniform/dynamic_index/read.wgsl.expected.spvasm

@@ -1,12 +1,13 @@
 ; SPIR-V
 ; Version: 1.3
 ; Generator: Google Tint Compiler; 0
-; Bound: 68
+; Bound: 65
 ; Schema: 0
                OpCapability Shader
                OpMemoryModel Logical GLSL450
-               OpEntryPoint GLCompute %main "main" %tint_symbol
+               OpEntryPoint GLCompute %main "main" %idx_1
                OpExecutionMode %main LocalSize 1 1 1
+               OpName %idx_1 "idx_1"
                OpName %S "S"
                OpMemberName %S 0 "arr"
                OpName %Inner "Inner"
@@ -22,8 +23,10 @@
                OpMemberName %Inner 9 "j"
                OpMemberName %Inner 10 "k"
                OpName %s "s"
-               OpName %tint_symbol "tint_symbol"
+               OpName %main_inner "main_inner"
+               OpName %idx "idx"
                OpName %main "main"
+               OpDecorate %idx_1 BuiltIn LocalInvocationIndex
                OpDecorate %S Block
                OpMemberDecorate %S 0 Offset 0
                OpMemberDecorate %Inner 0 Offset 0
@@ -46,10 +49,11 @@
                OpDecorate %s NonWritable
                OpDecorate %s Binding 0
                OpDecorate %s DescriptorSet 0
-               OpDecorate %tint_symbol BuiltIn LocalInvocationIndex
+       %uint = OpTypeInt 32 0
+%_ptr_Input_uint = OpTypePointer Input %uint
+      %idx_1 = OpVariable %_ptr_Input_uint Input
         %int = OpTypeInt 32 1
       %v3int = OpTypeVector %int 3
-       %uint = OpTypeInt 32 0
      %v3uint = OpTypeVector %uint 3
       %float = OpTypeFloat 32
     %v3float = OpTypeVector %float 3
@@ -66,10 +70,8 @@
           %S = OpTypeStruct %_arr_Inner_uint_8
 %_ptr_Uniform_S = OpTypePointer Uniform %S
           %s = OpVariable %_ptr_Uniform_S Uniform
-%_ptr_Input_uint = OpTypePointer Input %uint
-%tint_symbol = OpVariable %_ptr_Input_uint Input
        %void = OpTypeVoid
-         %22 = OpTypeFunction %void
+         %22 = OpTypeFunction %void %uint
      %uint_0 = OpConstant %uint 0
 %_ptr_Uniform_v3int = OpTypePointer Uniform %v3int
      %uint_1 = OpConstant %uint 1
@@ -85,34 +87,33 @@
 %_ptr_Uniform_v2int = OpTypePointer Uniform %v2int
      %uint_7 = OpConstant %uint 7
 %_ptr_Uniform_mat2v3float = OpTypePointer Uniform %mat2v3float
-       %main = OpFunction %void None %22
-         %25 = OpLabel
-         %27 = OpLoad %uint %tint_symbol
-         %29 = OpAccessChain %_ptr_Uniform_v3int %s %uint_0 %27 %uint_0
+         %60 = OpTypeFunction %void
+ %main_inner = OpFunction %void None %22
+        %idx = OpFunctionParameter %uint
+         %26 = OpLabel
+         %29 = OpAccessChain %_ptr_Uniform_v3int %s %uint_0 %idx %uint_0
          %30 = OpLoad %v3int %29
-         %31 = OpLoad %uint %tint_symbol
-         %34 = OpAccessChain %_ptr_Uniform_int %s %uint_0 %31 %uint_1
-         %35 = OpLoad %int %34
-         %36 = OpLoad %uint %tint_symbol
-         %39 = OpAccessChain %_ptr_Uniform_v3uint %s %uint_0 %36 %uint_2
-         %40 = OpLoad %v3uint %39
-         %41 = OpLoad %uint %tint_symbol
-         %44 = OpAccessChain %_ptr_Uniform_uint %s %uint_0 %41 %uint_3
-         %45 = OpLoad %uint %44
-         %46 = OpLoad %uint %tint_symbol
-         %48 = OpAccessChain %_ptr_Uniform_v3float %s %uint_0 %46 %uint_4
-         %49 = OpLoad %v3float %48
-         %50 = OpLoad %uint %tint_symbol
-         %53 = OpAccessChain %_ptr_Uniform_float %s %uint_0 %50 %uint_5
-         %54 = OpLoad %float %53
-         %55 = OpLoad %uint %tint_symbol
-         %58 = OpAccessChain %_ptr_Uniform_v2int %s %uint_0 %55 %uint_6
-         %59 = OpLoad %v2int %58
-         %60 = OpLoad %uint %tint_symbol
-         %62 = OpAccessChain %_ptr_Uniform_v2int %s %uint_0 %60 %uint_7
-         %63 = OpLoad %v2int %62
-         %64 = OpLoad %uint %tint_symbol
-         %66 = OpAccessChain %_ptr_Uniform_mat2v3float %s %uint_0 %64 %uint_8
-         %67 = OpLoad %mat2v3float %66
+         %33 = OpAccessChain %_ptr_Uniform_int %s %uint_0 %idx %uint_1
+         %34 = OpLoad %int %33
+         %37 = OpAccessChain %_ptr_Uniform_v3uint %s %uint_0 %idx %uint_2
+         %38 = OpLoad %v3uint %37
+         %41 = OpAccessChain %_ptr_Uniform_uint %s %uint_0 %idx %uint_3
+         %42 = OpLoad %uint %41
+         %44 = OpAccessChain %_ptr_Uniform_v3float %s %uint_0 %idx %uint_4
+         %45 = OpLoad %v3float %44
+         %48 = OpAccessChain %_ptr_Uniform_float %s %uint_0 %idx %uint_5
+         %49 = OpLoad %float %48
+         %52 = OpAccessChain %_ptr_Uniform_v2int %s %uint_0 %idx %uint_6
+         %53 = OpLoad %v2int %52
+         %55 = OpAccessChain %_ptr_Uniform_v2int %s %uint_0 %idx %uint_7
+         %56 = OpLoad %v2int %55
+         %58 = OpAccessChain %_ptr_Uniform_mat2v3float %s %uint_0 %idx %uint_8
+         %59 = OpLoad %mat2v3float %58
+               OpReturn
+               OpFunctionEnd
+       %main = OpFunction %void None %60
+         %62 = OpLabel
+         %64 = OpLoad %uint %idx_1
+         %63 = OpFunctionCall %void %main_inner %64
                OpReturn
                OpFunctionEnd