[sqlite] in-code documentation for Mem->type

[Bernhard Döbler]

Hello,

vcdbeInt.h reads:

** Each value has a manifest type. The manifest type of the value stored
** in a Mem struct is returned by the MemType(Mem*) macro. The type is
** one of SQLITE_NULL, SQLITE_INTEGER, SQLITE_REAL, SQLITE_TEXT or
** SQLITE_BLOB.
*/
struct Mem {
  i64 i;              /* Integer value */
  int n;              /* Number of characters in string value, including
'\0' */
  u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn,
etc. */
  u8  type;           /* One of MEM_Null, MEM_Str, etc. */

In the block comment SQLITE_REAL must obviously be SQLITE_FLOAT
In the inline-comment for the "type" member it must not be MEM_Null and the
like since MEM_Null != SQLITE_NULL
According to my understanding the MEM_* constants are used for the
"flags"-member indicating which members (string, float, integer) are validly
set.

Happy easter to all readers,
Bernhard