webgpu.h: Fix WGPU_WHOLE_SIZE causing linking errors.

The symbol was not marked as static and would cause linking errors
because it would be defined in multiple translation units. Replace it
with a more traditional C-style #define.

Change-Id: I19151884b7e8e171f829ffa47b1d119aff12ff99
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/15740
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/generator/templates/webgpu.h b/generator/templates/webgpu.h
index 52005ac..bae0a53 100644
--- a/generator/templates/webgpu.h
+++ b/generator/templates/webgpu.h
@@ -73,7 +73,7 @@
 #include <stddef.h>
 #include <stdbool.h>
-const uint64_t WGPU_WHOLE_SIZE = 0xffffffffffffffffULL; // UINT64_MAX
+#define WGPU_WHOLE_SIZE (0xffffffffffffffffULL)
 typedef uint32_t WGPUFlags;