Enable SQLITE_ENABLE_SNAPSHOT in the Xcode GRDB framework

Author: groue

Support/GRDBDeploymentTarget.xcconfig

@@ -2,7 +2,7 @@ IPHONEOS_DEPLOYMENT_TARGET = 13.0
 MACOSX_DEPLOYMENT_TARGET = 10.15
 TVOS_DEPLOYMENT_TARGET = 13.0
 WATCHOS_DEPLOYMENT_TARGET = 7.0
-OTHER_SWIFT_FLAGS = $(inherited) -D SQLITE_ENABLE_FTS5
+OTHER_SWIFT_FLAGS = $(inherited) -D SQLITE_ENABLE_FTS5 -D SQLITE_ENABLE_SNAPSHOT
 
 //// Compile with all opt-in APIs
 //GCC_PREPROCESSOR_DEFINITIONS = $(inherited) GRDB_SQLITE_ENABLE_PREUPDATE_HOOK=1