Change file naming

This is a follow-up to previous commit.

include/BH/Common.h

@@ -0,0 +1,25 @@
+#ifndef BH_COMMON_H
+#define BH_COMMON_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define BH_OK           0x0000
+#define BH_ERROR        0x0001
+#define BH_NOIMPL       0x0002
+#define BH_OOM          0x0003
+#define BH_INVALID      0x0004
+#define BH_FOUND        0x0005
+#define BH_NOTFOUND     0x0006
+#define BH_TIMEOUT      0x0007
+
+#define BH_UNUSED(x)    (void)(x)
+#define BH_PTR2INT(x)   ((intptr_t)(x))
+#define BH_INT2PTR(x)   ((void*)(x))
+
+
+typedef int (*BH_EqualCallback)(const void *, const void *);
+typedef size_t (*BH_HashCallback)(const void *);
+
+#endif /* BH_COMMON_H */
+