[shuffle] Move utils to new structure.

The name `core` was decided fit better with the base language for the
IR. This CL moves the `core/` folder to `utils/` and moves the files
into the correct subdirectories. The build targets and namespaces are
not updated as part of the move and will be fixed up in later CLs.

Bug: tint:1988
Change-Id: I1fc4414c86b28e1669af2d2d07340ecfdd9ba681
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/142361
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
diff --git a/src/tint/lang/base/builtin/number.h b/src/tint/lang/base/builtin/number.h
index 6563baa..68d6839 100644
--- a/src/tint/lang/base/builtin/number.h
+++ b/src/tint/lang/base/builtin/number.h
@@ -21,10 +21,10 @@
 #include <limits>
 #include <optional>
 
-#include "src/tint/core/compiler_macros.h"
-#include "src/tint/core/result.h"
-#include "src/tint/core/string_stream.h"
-#include "src/tint/core/traits.h"
+#include "src/tint/utils/macros/compiler.h"
+#include "src/tint/utils/result/result.h"
+#include "src/tint/utils/text/string_stream.h"
+#include "src/tint/utils/traits/traits.h"
 
 // Forward declaration
 namespace tint {