glsl: Add missing cstdint include for uint32_t

Change-Id: I0d5a8b5e844871028cae874b962b55b1af16fc54
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/80880
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: James Price <jrprice@google.com>
diff --git a/src/writer/glsl/version.h b/src/writer/glsl/version.h
index 14126e7..8bc0df9 100644
--- a/src/writer/glsl/version.h
+++ b/src/writer/glsl/version.h
@@ -15,6 +15,8 @@
 #ifndef SRC_WRITER_GLSL_VERSION_H_
 #define SRC_WRITER_GLSL_VERSION_H_
 
+#include <cstdint>
+
 namespace tint::writer::glsl {
 
 /// A structure representing the version of GLSL to be generated.