Fixes to the appendvfs.c extension. Add the "sqltclsh" application that

uses appendvfs.c to find its scripts.

FossilOrigin-Name: ee248b529c2396c5480fb99b0a1dc31032627ec8241eca4a8c0fff257bb4a088

tool/sqltclsh.c.in

@@ -0,0 +1,42 @@
+/*
+** This is the source code to a "tclsh" that has SQLite built-in.
+**
+** The startup script is located as follows:
+**
+**   (1)  Open the executable as an appended SQLite database and try to
+**        read the startup script out of that database.
+**
+**   (2)  If the first argument is a readable file, try to open that file
+**        as an SQLite database and read the startup script out of that
+**        database.
+**
+**   (3)  If the first argument is a readable file with a ".tcl" extension,
+**        then try to run that script directly.
+**
+** If none of the above steps work, then the program runs as an interactive
+** tclsh.
+*/
+#define TCLSH_INIT_PROC sqlite3_tclapp_init_proc
+#define SQLITE_ENABLE_DBSTAT_VTAB 1
+#undef SQLITE_THREADSAFE
+#define SQLITE_THREADSAFE 0
+#undef SQLITE_ENABLE_COLUMN_METADATA
+#define SQLITE_OMIT_DECLTYPE 1
+#define SQLITE_OMIT_DEPRECATED 1
+#define SQLITE_OMIT_PROGRESS_CALLBACK 1
+#define SQLITE_OMIT_SHARED_CACHE 1
+#define SQLITE_DEFAULT_MEMSTATUS 0
+#define SQLITE_MAX_EXPR_DEPTH 0
+INCLUDE sqlite3.c
+INCLUDE $ROOT/ext/misc/appendvfs.c
+INCLUDE $ROOT/src/tclsqlite.c
+
+const char *sqlite3_tclapp_init_proc(Tcl_Interp *interp){
+  (void)interp;
+  sqlite3_appendvfs_init(0,0,0);
+  return
+BEGIN_STRING
+INCLUDE $ROOT/tool/sqltclsh.tcl
+END_STRING
+;
+}