Add tests derived from VK-GL-CTS

This adds SPIR-V assembly and WGSL tests derived from VK-GL-CTS commit
571256871c2e2f03995373e1e4a02958d8cd8cf5. The following procedure was
followed:

- Those .amber files in VK-GL-CTS wholly owned by Google were
  identified

- All GLSL and SPIR-V shaders were extracted from the Amber files and
  converted into SPIR-V binaries

- The compact-ids pass of spirv-opt was applied to each binary

- Duplicate binaries were removed

- spirv-opt -O was used to obtain an optimized version of each remaining
  binary, with duplicates discarded

- Binaries that failed validation using spirv-val with target
  environment SPIR-V 1.3 were discarded

- Those binaries that tint could not successfully convert into WGSL were
  put aside for further investigation

- SPIR-V assembly versions of the remaining binaries are included in
  this CL

- test-runner with -generate-expected and -generate-skip was used to
  generate expected .spvasm, .msl, .hlsl and .wgsl outputs for these
  SPIR-V assembly tests

- Each successfully-generated .expected.wgsl is included in this CL
  again, as a WGLSL test

- test-runner with -generate-expected and -generate-skip was used again,
  to generate expected outputs for these WGSL tests

Change-Id: Ibe9baf2729cf97e0b633db9a426f53362a5de540
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/58842
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>

test/vk-gl-cts/graphicsfuzz/struct-array-index/0.spvasm.expected.msl

@@ -0,0 +1,58 @@
+#include <metal_stdlib>
+
+using namespace metal;
+struct struct_base {
+  int data;
+  int leftIndex;
+  int rightIndex;
+};
+struct buf0 {
+  /* 0x0000 */ packed_float2 injectionSwitch;
+};
+struct tint_array_wrapper {
+  struct_base arr[3];
+};
+struct main_out {
+  float4 x_GLF_color_1;
+};
+struct tint_symbol_1 {
+  float4 x_GLF_color_1 [[color(0)]];
+};
+
+void main_1(constant buf0& x_8, thread tint_array_wrapper* const tint_symbol_8, thread float4* const tint_symbol_9) {
+  int index = 0;
+  struct_base const tint_symbol_3 = {.data=1, .leftIndex=1, .rightIndex=1};
+  struct_base const tint_symbol_4 = {.data=1, .leftIndex=1, .rightIndex=1};
+  struct_base const tint_symbol_5 = {.data=1, .leftIndex=1, .rightIndex=1};
+  tint_array_wrapper const tint_symbol_6 = {.arr={tint_symbol_3, tint_symbol_4, tint_symbol_5}};
+  *(tint_symbol_8) = tint_symbol_6;
+  index = 1;
+  (*(tint_symbol_8)).arr[1].rightIndex = 1;
+  int const x_39 = (*(tint_symbol_8)).arr[1].leftIndex;
+  if ((x_39 == 1)) {
+    float const x_45 = x_8.injectionSwitch.x;
+    int const x_48 = (*(tint_symbol_8)).arr[int(x_45)].rightIndex;
+    index = x_48;
+  } else {
+    float const x_50 = x_8.injectionSwitch.y;
+    int const x_53 = (*(tint_symbol_8)).arr[int(x_50)].leftIndex;
+    index = x_53;
+  }
+  int const x_55 = (*(tint_symbol_8)).arr[1].leftIndex;
+  if ((x_55 == 1)) {
+    *(tint_symbol_9) = float4(1.0f, 0.0f, 0.0f, 1.0f);
+  } else {
+    *(tint_symbol_9) = float4(1.0f, 1.0f, 1.0f, 1.0f);
+  }
+  return;
+}
+
+fragment tint_symbol_1 tint_symbol(constant buf0& x_8 [[buffer(0)]]) {
+  thread tint_array_wrapper tint_symbol_10 = {};
+  thread float4 tint_symbol_11 = 0.0f;
+  main_1(x_8, &(tint_symbol_10), &(tint_symbol_11));
+  main_out const tint_symbol_2 = {.x_GLF_color_1=tint_symbol_11};
+  tint_symbol_1 const tint_symbol_7 = {.x_GLF_color_1=tint_symbol_2.x_GLF_color_1};
+  return tint_symbol_7;
+}
+