[caching] handle VARIABLE_HINT_SIZE incompat flag

base/bits.h

@@ -0,0 +1,26 @@
+#ifndef BASE_BITS_H
+#define BASE_BITS_H
+
+//----------------------------------------------------------------
+
+namespace base {
+	template <typename T>
+	bool test_bit(T flag, unsigned bit) {
+		return flag & (1 << bit);
+	}
+
+	template <typename T>
+	void set_bit(T &flag, unsigned bit) {
+		flag = flag | (1 << bit);
+	}
+
+	template <typename T>
+	void clear_bit(T &flag, unsigned bit) {
+		flag = flag & ~(1 << bit);
+	}
+}
+
+//----------------------------------------------------------------
+
+#endif
+