Provide the ability to use the SELECTTRACE() debugging macro outside of the

select.c source file.  Use this to add a new SELECTTRACE() entry in
window.c for improved tracing of window-function parse-tree rewriting.

FossilOrigin-Name: 30c6d895b573d5f2a53487b3b7a0d20be7e382c7a0bc87336bd43fbd2fa89bf4

src/global.c

@@ -300,6 +300,11 @@ sqlite3_uint64 sqlite3NProfileCnt = 0;
 int sqlite3PendingByte = 0x40000000;
 #endif
 
+/*
+** Flags for select tracing and the ".selecttrace" macro of the CLI
+*/
+/**/ u32 sqlite3SelectTrace = 0;
+
 #include "opcodes.h"
 /*
 ** Properties of opcodes.  The OPFLG_INITIALIZER macro is