Remove #pragma
No need for this pragma anymore as ISO C11 allows anonymous structs. [See](https://gcc.gnu.org/onlinedocs/gcc/Unnamed-Fields.html#Unnamed-Fields).
#ifndef _NANOCLR_RUNTIME__HEAPBLOCK_H_
#define _NANOCLR_RUNTIME__HEAPBLOCK_H_
-#ifdef __arm__
-// ARM compiler does not allow anonymous structs by default
-#pragma anon_unions
-#endif
-
////////////////////////////////////////////////////////////////////////////////////////////////////
#define CLR_RT_HEAPBLOCK_RAW_ID( dataType, flags, size ) ( (dataType & 0x000000FF) | ((flags & 0x000000FF) << 8) | ((size & 0x0000FFFF) << 16))
