switch to using 32-bit offsets for leaf records over the pointers

src/base/base_core.c

@@ -288,6 +288,12 @@ memory_is_zero(void *ptr, U64 size)
   return result;
 }
 
+internal void UBSAN_NO_ALIGN
+memory_write16(void *ptr, U16 v)
+{
+  MemoryCopy(ptr, &v, sizeof(v));
+}
+
 internal void UBSAN_NO_ALIGN
 memory_write32(void *ptr, U32 v)
 {

src/base/base_core.h

@@ -1009,6 +1009,7 @@ internal F32 sign_from_side_F32(Side side);
 
 internal B32 memory_is_zero(void *ptr, U64 size);
 
+internal void memory_write16(void *ptr, U16 v);
 internal void memory_write32(void *ptr, U32 v);
 
 internal U8  memory_read8(void *ptr);