moved Guid struct and related helpers to base

src/base/base_core.h

@@ -486,6 +486,19 @@ struct TxtRng
   TxtPt max;
 };
 
+////////////////////////////////
+//~ Globally Unique Ids
+
+typedef struct Guid Guid;
+struct Guid
+{
+  U32 data1;
+  U16 data2;
+  U16 data3;
+  U8  data4[8];
+};
+StaticAssert(sizeof(Guid) == 16, g_guid_size_check);
+
 ////////////////////////////////
 //~ NOTE(allen): Constants