[patch,v850] make sbrk -msda-proof

[DJ Delorie]

The use of "extern char heap_start;" in sbrk triggers an addressing
mode change with -msda=4, leading to link-time errors.  Changing it to
an unspecified-sized array forces gcc to use the most pessimum
addressing mode, which will always work with linker-defined symbols.
Ok?

	* libc/sys/sysnecv850/sbrk.c (_sbrk): Change heap_start to be an
	array of undefined size, to avoid problems when compiled with
	-msda=4.

	* v850/sbrk.c (_sbrk): Change heap_start to be an array of
	undefined size, to avoid problems when compiled with -msda=4.

Index: newlib/libc/sys/sysnecv850/sbrk.c
===================================================================
RCS file: /cvs/src/src/newlib/libc/sys/sysnecv850/sbrk.c,v
retrieving revision 1.2
diff -p -U5 -r1.2  newlib/libc/sys/sysnecv850/sbrk.c
--- newlib/libc/sys/sysnecv850/sbrk.c	27 May 2011 10:46:47 -0000	1.2
+++ newlib/libc/sys/sysnecv850/sbrk.c	1 Oct 2012 21:36:29 -0000
@@ -4,17 +4,17 @@
 #include "sys/syscall.h"
 
 caddr_t
 _sbrk (int incr)
 {
-  extern char   heap_start;	/* Defined by the linker script.  */
+  extern char   heap_start[];	/* Defined by the linker script.  */
   static char * heap_end = NULL;
   char *        prev_heap_end;
   char *        sp = (char *) & sp;
 
   if (heap_end == NULL)
-    heap_end = & heap_start;
+    heap_end = heap_start;
 
   prev_heap_end = heap_end;
 
   if (heap_end + incr > sp)
     {

Index: libgloss/v850/sbrk.c
===================================================================
RCS file: /cvs/src/src/libgloss/v850/sbrk.c,v
retrieving revision 1.2
diff -p -U5 -r1.2  libgloss/v850/sbrk.c
--- libgloss/v850/sbrk.c	27 May 2011 10:46:48 -0000	1.2
+++ libgloss/v850/sbrk.c	1 Oct 2012 21:36:30 -0000
@@ -4,17 +4,17 @@
 #include "sys/syscall.h"
 
 caddr_t
 _sbrk (int incr)
 {
-  extern char   heap_start;		/* Defined by the linker script. */
+  extern char   heap_start[];		/* Defined by the linker script. */
   static char * heap_end = NULL;
   char *        prev_heap_end;
   char *        sp = (char *) & sp;
 
   if (heap_end == NULL)
-    heap_end = & heap_start;
+    heap_end = heap_start;
 
   prev_heap_end = heap_end;
 
   if (heap_end + incr > sp)
     {