make stg_arg_bitmaps public, and available via the GHCi linker (#3672)

includes/rts/storage/InfoTables.h

@@ -290,6 +290,9 @@ typedef struct {
 #endif
 } StgFunInfoTable;
 
+// canned bitmap for each arg type, indexed by constants in FunTypes.h
+extern StgWord stg_arg_bitmaps[];
+
 /* -----------------------------------------------------------------------------
    Return info tables
    -------------------------------------------------------------------------- */

rts/Apply.h

@@ -23,7 +23,4 @@ extern RTS_PRIVATE StgWord stg_stack_save_entries[];
 extern RTS_PRIVATE StgFun *stg_stack_save_entries[];
 #endif
 
-// canned bitmap for each arg type
-extern RTS_PRIVATE StgWord stg_arg_bitmaps[];
-
 #endif /* APPLY_H */

rts/Linker.c

@@ -966,6 +966,7 @@ typedef struct _RtsSymbolVal {
       SymI_HasProto(stg_writeTVarzh)			\
       SymI_HasProto(stg_yieldzh)                        \
       SymI_NeedsProto(stg_interp_constr_entry)          \
+      SymI_HasProto(stg_arg_bitmaps)                    \
       SymI_HasProto(alloc_blocks_lim)                   \
       SymI_HasProto(g0)                                 \
       SymI_HasProto(allocate)                           \