support using the sqlite3 from trunk rather than a released version

The build tag `sqlite_trunk` results in using `sqlite3_trunk.c` instead of `sqlite3.c`.

The current `sqlite3_trunk.c` results from building the amalgamation from
sqlite/sqlite@0f7f9ab
using `configure --all`.

`sqlite3.h` is still just the released version.

Updates tailscale/corp#37997

Signed-off-by: Percy Wegmann <percy@tailscale.com>

Author: oxtoacart

.github/workflows/test-sqlite.yml

@@ -31,9 +31,8 @@ jobs:
 
     - name: Race
       run: go test -v -race ./...
-
-    - name: Race with sqlite_enable_api_armor and sqlite_enable_tmstmpvfs
-      run: go test -v -race -tags sqlite_enable_api_armor,sqlite_enable_tmstmpvfs
+    - name: Race with sqlite_trunk, sqlite_enable_api_armor and sqlite_enable_tmstmpvfs
+      run: go test -v -race -tags sqlite_trunk,sqlite_enable_api_armor,sqlite_enable_tmstmpvfs
 
     - name: No CGO build
       run: CGO_ENABLED=0 go install ./...

cgosqlite/cgosqlite.go

@@ -8,6 +8,8 @@ package cgosqlite
 // One exception is we do not use SQLITE_OMIT_DECLTYPE, as the design
 // of the database/sql driver seems to require it.
 
+#cgo !sqlite_trunk CFLAGS: -DSQLITE_RELEASE
+#cgo sqlite_trunk CFLAGS: -DSQLITE_TRUNK
 #cgo CFLAGS: -DSQLITE_THREADSAFE=2
 #cgo CFLAGS: -DSQLITE_DQS=0
 #cgo CFLAGS: -DSQLITE_DEFAULT_MEMSTATUS=0

cgosqlite/sqlite3.c

@@ -1,3 +1,5 @@
+#ifdef SQLITE_RELEASE
+
 /******************************************************************************
 ** This file is an amalgamation of many separate C source files from SQLite
 ** version 3.51.2.  By combining all the individual C code files into this
@@ -265950,3 +265952,6 @@ SQLITE_API int sqlite3_stmt_init(
 SQLITE_API const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
 #endif /* SQLITE_AMALGAMATION */
 /************************** End of sqlite3.c ******************************/
+
+
+#endif