Fix a typo in the IS_BIG_INT macro used by coverage test instrumentation.

FossilOrigin-Name: 5314ca3928dab1c76fa4ec5dbe110e3212c95e9f
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 79161a5..154116e 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -277,7 +277,7 @@
 ** to fit in 32-bits.  This macro is used inside of various testcase()
 ** macros to verify that we have tested SQLite for large-file support.
 */
-#define IS_BIG_INT(X)  (((X)&(i64)0xffffffff)!=0)
+#define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)
 
 /*
 ** The macro unlikely() is a hint that surrounds a boolean