Merge in all the 3.9.0 updates from trunk.

FossilOrigin-Name: 29444149342fc6b1ea8cd34c2c8e1fcb06eaa7ed

src/sqliteInt.h

@@ -196,6 +196,7 @@
 #      include <intrin.h>
 #      pragma intrinsic(_byteswap_ushort)
 #      pragma intrinsic(_byteswap_ulong)
+#      pragma intrinsic(_ReadWriteBarrier)
 #    else
 #      include <cmnintrin.h>
 #    endif
@@ -1918,6 +1919,12 @@ struct Index {
 /* Return true if index X is a UNIQUE index */
 #define IsUniqueIndex(X)      ((X)->onError!=OE_None)
 
+/* The Index.aiColumn[] values are normally positive integer.  But
+** there are some negative values that have special meaning:
+*/
+#define XN_ROWID     (-1)     /* Indexed column is the rowid */
+#define XN_EXPR      (-2)     /* Indexed column is an expression */
+
 /*
 ** Each sample stored in the sqlite_stat3 table is represented in memory 
 ** using a structure of this type.  See documentation at the top of the
@@ -3510,6 +3517,7 @@ void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
   void sqlite3UnlinkAndDeleteTrigger(sqlite3*,int,const char*);
   u32 sqlite3TriggerColmask(Parse*,Trigger*,ExprList*,int,int,Table*,int);
 # define sqlite3ParseToplevel(p) ((p)->pToplevel ? (p)->pToplevel : (p))
+# define sqlite3IsToplevel(p) ((p)->pToplevel==0)
 #else
 # define sqlite3TriggersExist(B,C,D,E,F) 0
 # define sqlite3DeleteTrigger(A,B)
@@ -3519,6 +3527,7 @@ void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
 # define sqlite3CodeRowTriggerDirect(A,B,C,D,E,F)
 # define sqlite3TriggerList(X, Y) 0
 # define sqlite3ParseToplevel(p) p
+# define sqlite3IsToplevel(p) 1
 # define sqlite3TriggerColmask(A,B,C,D,E,F,G) 0
 #endif