gas/avr: Prevent incorrect overflow errors for diff fixups.

When fixups are converted to a difference type within md_apply_fix, we
previously left the contents of VALP (the value that was initially
computed within write.c:fixup_segment) unchanged.  This is harmless,
except that this value is used within write.c:fixup_segment once we
return from md_apply_fix to perform an overflow check.

In some cases, the value computed in write.c:fixup_segment is so wrong
that an overflow error can be triggered.  These errors are incorrect.

This patch avoids the overflow errors by adjusting the value in
write.c:fixup_segment using the VALP pointer in md_apply_fix.

A test for this issue is included.

gas/ChangeLog:

	* config/tc-avr.c (md_apply_fix): Update the contents of VALP for
	diff fixups.

gas/testsuite/ChangeLog:

	* gas/avr/large-debug-line-table.d: New file.
	* gas/avr/large-debug-line-table.s: New file.

1 files changed, 1 insertions, 0 deletions

diff --git a/gas/config/tc-avr.c b/gas/config/tc-avr.c
index 19326a1..5a0b405 100644
--- a/gas/config/tc-avr.c
+++ b/gas/config/tc-avr.c
@@ -1344,6 +1344,7 @@ md_apply_fix (fixS *fixP, valueT * valP, segT seg)
 
       value = S_GET_VALUE (fixP->fx_addsy) +
           fixP->fx_offset - S_GET_VALUE (fixP->fx_subsy);
+      *valP = value;
 
       fixP->fx_subsy = NULL;
   }