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/shader_io/interpolate_input_struct.wgsl.expected.glsl

@@ -0,0 +1,30 @@
+#version 310 es
+precision mediump float;
+
+layout(location = 0) in float none_1;
+layout(location = 1) flat in float tint_symbol_3;
+layout(location = 2) in float perspective_center_1;
+layout(location = 3) centroid in float perspective_centroid_1;
+layout(location = 4) in float perspective_sample_1;
+layout(location = 5) in float linear_center_1;
+layout(location = 6) centroid in float linear_centroid_1;
+layout(location = 7) in float linear_sample_1;
+struct In {
+  float none;
+  float tint_symbol;
+  float perspective_center;
+  float perspective_centroid;
+  float perspective_sample;
+  float linear_center;
+  float linear_centroid;
+  float linear_sample;
+};
+
+void tint_symbol_1(In tint_symbol_2) {
+}
+
+void main() {
+  In tint_symbol_4 = In(none_1, tint_symbol_3, perspective_center_1, perspective_centroid_1, perspective_sample_1, linear_center_1, linear_centroid_1, linear_sample_1);
+  tint_symbol_1(tint_symbol_4);
+  return;
+}