Fast forward to sync public repo.

Compile math.sinh(), math.cosh(), math.tanh() and math.random().
Compile various io.*() functions.
Drive the GC forward on string allocations in the parser.
Improve KNUM fuse vs. load heuristics.
Add abstract C call handling to IR.

src/lj_lib.h

@@ -90,4 +90,9 @@ LJ_FUNC void lj_lib_register(lua_State *L, const char *libname,
 #define LIBINIT_FFID	0xfe
 #define LIBINIT_END	0xff
 
+/* Exported library functions. */
+
+typedef struct RandomState RandomState;
+LJ_FUNC uint64_t LJ_FASTCALL lj_math_random_step(RandomState *rs);
+
 #endif