indicates to the C program that the memset() routine is available
to set blocks of memory.
+d_memrchr (d_memrchr.U):
+ This variable conditionally defines the HAS_MEMRCHR symbol, which
+ indicates to the C program that the memrchr() routine is available
+ to return a pointer to the last occurrence of a byte in a memory
+ area (or NULL if not found).
+
d_mkdir (d_mkdir.U):
This variable conditionally defines the HAS_MKDIR symbol, which
indicates to the C program that the mkdir() routine is available