tint->dawn: Shuffle source tree in preperation of merging repos

docs/    -> docs/tint/
fuzzers/ -> src/tint/fuzzers/
samples/ -> src/tint/cmd/
src/     -> src/tint/
test/    -> test/tint/

BUG=tint:1418,tint:1433

Change-Id: Id2aa79f989aef3245b80ef4aa37a27ff16cd700b
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/80482
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

test/tint/vk-gl-cts/graphicsfuzz/discard-in-loop-in-function/0-opt.spvasm

@@ -0,0 +1,77 @@
+               OpCapability Shader
+          %1 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main" %gl_FragCoord %_GLF_color
+               OpExecutionMode %main OriginUpperLeft
+               OpSource ESSL 310
+               OpName %main "main"
+               OpName %f_ "f("
+               OpName %buf0 "buf0"
+               OpMemberName %buf0 0 "injectionSwitch"
+               OpName %_ ""
+               OpName %gl_FragCoord "gl_FragCoord"
+               OpName %_GLF_color "_GLF_color"
+               OpMemberDecorate %buf0 0 Offset 0
+               OpDecorate %buf0 Block
+               OpDecorate %_ DescriptorSet 0
+               OpDecorate %_ Binding 0
+               OpDecorate %gl_FragCoord BuiltIn FragCoord
+               OpDecorate %_GLF_color Location 0
+       %void = OpTypeVoid
+          %9 = OpTypeFunction %void
+      %float = OpTypeFloat 32
+    %float_1 = OpConstant %float 1
+    %v2float = OpTypeVector %float 2
+       %buf0 = OpTypeStruct %v2float
+%_ptr_Uniform_buf0 = OpTypePointer Uniform %buf0
+          %_ = OpVariable %_ptr_Uniform_buf0 Uniform
+        %int = OpTypeInt 32 1
+      %int_0 = OpConstant %int 0
+       %uint = OpTypeInt 32 0
+     %uint_1 = OpConstant %uint 1
+%_ptr_Uniform_float = OpTypePointer Uniform %float
+       %bool = OpTypeBool
+    %v4float = OpTypeVector %float 4
+%_ptr_Input_v4float = OpTypePointer Input %v4float
+%gl_FragCoord = OpVariable %_ptr_Input_v4float Input
+%_ptr_Input_float = OpTypePointer Input %float
+    %float_0 = OpConstant %float 0
+      %false = OpConstantFalse %bool
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+ %_GLF_color = OpVariable %_ptr_Output_v4float Output
+         %26 = OpConstantComposite %v4float %float_1 %float_0 %float_0 %float_1
+       %main = OpFunction %void None %9
+         %27 = OpLabel
+         %28 = OpFunctionCall %void %f_
+               OpStore %_GLF_color %26
+               OpReturn
+               OpFunctionEnd
+         %f_ = OpFunction %void None %9
+         %29 = OpLabel
+               OpBranch %30
+         %30 = OpLabel
+               OpLoopMerge %31 %32 None
+               OpBranch %33
+         %33 = OpLabel
+         %34 = OpAccessChain %_ptr_Uniform_float %_ %int_0 %uint_1
+         %35 = OpLoad %float %34
+         %36 = OpFOrdGreaterThan %bool %float_1 %35
+               OpSelectionMerge %37 None
+               OpBranchConditional %36 %38 %37
+         %38 = OpLabel
+         %39 = OpAccessChain %_ptr_Input_float %gl_FragCoord %uint_1
+         %40 = OpLoad %float %39
+         %41 = OpFOrdLessThan %bool %40 %float_0
+               OpSelectionMerge %42 None
+               OpBranchConditional %41 %43 %32
+         %43 = OpLabel
+               OpBranch %32
+         %42 = OpLabel
+               OpBranch %32
+         %32 = OpLabel
+               OpBranchConditional %false %30 %31
+         %37 = OpLabel
+               OpKill
+         %31 = OpLabel
+               OpReturn
+               OpFunctionEnd

test/tint/vk-gl-cts/graphicsfuzz/discard-in-loop-in-function/0-opt.wgsl

@@ -0,0 +1,51 @@
+struct buf0 {
+  injectionSwitch : vec2<f32>;
+};
+
+@group(0) @binding(0) var<uniform> x_7 : buf0;
+
+var<private> gl_FragCoord : vec4<f32>;
+
+var<private> x_GLF_color : vec4<f32>;
+
+fn f_() {
+  loop {
+    let x_35 : f32 = x_7.injectionSwitch.y;
+    if ((1.0 > x_35)) {
+      let x_40 : f32 = gl_FragCoord.y;
+      if ((x_40 < 0.0)) {
+        continue;
+      } else {
+        continue;
+      }
+      continue;
+    }
+    discard;
+
+    continuing {
+      if (false) {
+      } else {
+        break;
+      }
+    }
+  }
+  return;
+}
+
+fn main_1() {
+  f_();
+  x_GLF_color = vec4<f32>(1.0, 0.0, 0.0, 1.0);
+  return;
+}
+
+struct main_out {
+  @location(0)
+  x_GLF_color_1 : vec4<f32>;
+};
+
+@stage(fragment)
+fn main(@builtin(position) gl_FragCoord_param : vec4<f32>) -> main_out {
+  gl_FragCoord = gl_FragCoord_param;
+  main_1();
+  return main_out(x_GLF_color);
+}