Fix the Synopsis on OP_Concat.  Added test_addop_breakpoint() during
SQLITE_DEBUG.  Enhanced sqlite3VdbeChangeToNoop() to omit the instruction
if it is the most recent added.  Continue to fix problems with UPDATE
and WITHOUT ROWID.

FossilOrigin-Name: 9b6d9e106aaa3c2efb33d234d26cf08cd3c967b9
diff --git a/src/expr.c b/src/expr.c
index 24d866f..4a321db 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2214,9 +2214,9 @@
 void sqlite3ExprCodeGetColumnOfTable(
   Vdbe *v,        /* The VDBE under construction */
   Table *pTab,    /* The table containing the value */
-  int iTabCur,    /* The cursor for this table */
+  int iTabCur,    /* The table cursor.  Or the PK cursor for WITHOUT ROWID */
   int iCol,       /* Index of the column to extract */
-  int regOut      /* Extract the valud into this register */
+  int regOut      /* Extract the value into this register */
 ){
   if( iCol<0 || iCol==pTab->iPKey ){
     sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);