Add support for sqlite_math_functions tag (#1059)

Add support for SQLITE_ENABLE_MATH_FUNCTIONS compile-time option via the sqlite_math_functions build tag.

Co-authored-by: Dominik Kraus <dominik.kraus@nktek.de>

sqlite3_opt_math_functions.go

@@ -0,0 +1,14 @@
+// Copyright (C) 2022 Yasuhiro Matsumoto <mattn.jp@gmail.com>.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+// +build sqlite_math_functions
+
+package sqlite3
+
+/*
+#cgo CFLAGS: -DSQLITE_ENABLE_MATH_FUNCTIONS
+#cgo LDFLAGS: -lm
+*/
+import "C"