[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/texel_format.cc.tmpl b/src/tint/lang/base/builtin/texel_format.cc.tmpl
index 7292e85..546d1de 100644
--- a/src/tint/lang/base/builtin/texel_format.cc.tmpl
+++ b/src/tint/lang/base/builtin/texel_format.cc.tmpl
@@ -8,7 +8,7 @@
 --------------------------------------------------------------------------------
 */ -}}
 
-{{- Import "src/tint/core/templates/enums.tmpl.inc" -}}
+{{- Import "src/tint/utils/templates/enums.tmpl.inc" -}}
 {{- $enum := (Sem.Enum "texel_format") -}}
 
 #include "src/tint/lang/base/builtin/texel_format.h"