Disable the use of memory-mapped I/O if the SQLITE_DISABLE_MMAP macro is

defined.  Automatically define this macro for OpenBSD and QNX.  Other
systems are likely to be added to the disabled list over time.

FossilOrigin-Name: 8a4314a398c6c6efb25e6993c826b7e60d9bb1f9

src/sqliteInt.h

@@ -539,6 +539,14 @@ extern const int sqlite3one;
 # define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
 #endif
 
+/*
+** Disable MMAP on platforms where it is not supported
+*/
+#if defined(__OpenBSD__) || defined(__QNXNTO__)
+# undef SQLITE_DISABLE_MMAP
+# define SQLITE_DISABLE_MMAP 1
+#endif
+
 
 /*
 ** An instance of the following structure is used to store the busy-handler