It's

 module_t modules[] = {
  { "clisp",
...
{ "regexp", &module__regexp__subr_tab.subrs[0], &module__regexp__subr_tab_size, &module__regexp__object_tab[0], &module__regexp__object_tab_size, 0, &module__regexp__subr_tab_initdata[0], &module__regexp__object_tab_initdata[0], &module__regexp__init_function_1, &module__regexp__init_function_2, &module__regexp__fini_function , ((void *)0) },
...

using &module__regexp__object_tab[0] (an array-ref), and declared as

extern gcv_object_t module__regexp__object_tab[];

but defined in the other module as

struct module__regexp__object_tab_t {
  gcv_object_t _object_Kboolean;
  gcv_object_t _object_Kend;
  gcv_object_t _object_Kextended;
  gcv_object_t _object_Kignore_case;
  gcv_object_t _object_Knewline;
  gcv_object_t _object_Knosub;
  gcv_object_t _object_Knotbol;
  gcv_object_t _object_Knoteol;
  gcv_object_t _object_Kreturn_type;
  gcv_object_t _object_Kstart;
  gcv_object_t _object_regexp__make_match_boa;
  gcv_object_t _object__23_28_29;
} module__regexp__object_tab;

thus no array for the actual decl.

Reduced testcase:

extern int x[];
int *foo[] = { &x[0] };

----

int x;

We miss to wrap uses of non-automatic vars inside MEM_REFs for global initializers
(we do that for the IL already).

Doing this raises the question whether we shouldn't simply special-case
global var references and stream a type which each reference, materializing
a MEM_REF only when necessary (not sure if we know that at the point we are
materializing the initializer).

Anyway, short-term fix:

Index: gcc/lto-streamer-out.c
===================================================================
--- gcc/lto-streamer-out.c      (revision 208955)
+++ gcc/lto-streamer-out.c      (working copy)
@@ -313,6 +313,27 @@ lto_is_streamable (tree expr)
 }
 
 
+/* Wrap symbol references in *TP inside a type-preserving MEM_REF.  */
+
+static tree
+wrap_refs (tree *tp, int *ws, void *)
+{
+  tree t = *tp;
+  if (TREE_CODE (t) == VAR_DECL)
+    {
+      tree ptrtype = build_pointer_type (TREE_TYPE (t));
+      *tp = build2 (MEM_REF, TREE_TYPE (t),
+                   build1 (ADDR_EXPR, ptrtype, t),
+                   build_int_cst (ptrtype, 0));
+      *ws = 0;
+    }
+  else if (TREE_CODE (t) == CONSTRUCTOR)
+    ;
+  else if (!EXPR_P (t))
+    *ws = 0;
+  return NULL_TREE;
+}
+
 /* For EXPR lookup and return what we want to stream to OB as DECL_INITIAL.  */
 
 static tree
@@ -340,6 +361,14 @@ get_symbol_initial_value (struct output_
        initial = error_mark_node;
     }
 
+  /* Wrap all symbol references inside the initializer in a MEM_REF
+     to preserve the type at the use even in case the symbol is
+     prevailed by one with a different type.  We can safely skip this
+     during WPA.  */
+  if (!in_lto_p
+      && initial && initial != error_mark_node)
+    walk_tree (&initial, wrap_refs, NULL, NULL);
+
   return initial;
 }

Author: rguenth
Date: Mon Apr 14 08:35:22 2014
New Revision: 209359

URL: http://gcc.gnu.org/viewcvs?rev=209359&root=gcc&view=rev
Log:
2014-04-14  Richard Biener  <rguenther@suse.de>

	PR lto/60720
	* lto-streamer-out.c (wrap_refs): New function.
	(lto_output): Wrap symbol references in global initializes in
	type-preserving MEM_REFs.

	* gcc.dg/lto/pr60720_0.c: New testcase.
	* gcc.dg/lto/pr60720_1.c: Likewise.

Added:
    trunk/gcc/testsuite/gcc.dg/lto/pr60720_0.c
    trunk/gcc/testsuite/gcc.dg/lto/pr60720_1.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/lto-streamer-out.c
    trunk/gcc/testsuite/ChangeLog

Fixed on trunk sofar.

Author: rguenth
Date: Wed Apr 23 08:31:48 2014
New Revision: 209677

URL: http://gcc.gnu.org/viewcvs?rev=209677&root=gcc&view=rev
Log:
2014-04-23  Richard Biener  <rguenther@suse.de>

	Backport from mainline
	2014-04-14  Richard Biener  <rguenther@suse.de>

	PR lto/60720
	* lto-streamer-out.c (wrap_refs): New function.
	(lto_output): Wrap symbol references in global initializes in
	type-preserving MEM_REFs.

	* gcc.dg/lto/pr60720_0.c: New testcase.
	* gcc.dg/lto/pr60720_1.c: Likewise.

Added:
    branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/lto/pr60720_0.c
    branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/lto/pr60720_1.c
Modified:
    branches/gcc-4_9-branch/gcc/ChangeLog
    branches/gcc-4_9-branch/gcc/lto-streamer-out.c
    branches/gcc-4_9-branch/gcc/testsuite/ChangeLog

Fixed for 4.9.1.

Fixed.