* gdbarch.sh: Make the `default' field really default to zero, as

documented.

Bring COERCE_FLOAT_TO_DOUBLE under gdbarch's control.
* valops.c (COERCE_FLOAT_TO_DOUBLE): Rework definition to be
more function-like.
(default_coerce_float_to_double, standard_coerce_float_to_double):
New functions.
(value_arg_coerce): Adjust for new definition.
* value.h (default_coerce_float_to_double,
standard_coerce_float_to_double): New declarations for the above.
* gdbarch.sh (coerce_float_to_double): New entry, replacing macro.
* gdbarch.c, gdbarch.h: Regenerated.
* tm-alpha.h, tm-fr30.h, tm-m32r.h, tm-mips.h, tm-hppa.h,
tm-rs6000.h, tm-sh.h, tm-sparc.h (COERCE_FLOAT_TO_DOUBLE): Change
definitions.
* mips-tdep.c (mips_coerce_float_to_double): Supply our own custom
function here.
(mips_gdbarch_init): Install that as our coerce_float_to_double
function.

gdb/gdbarch.sh

@@ -180,6 +180,7 @@ f:2:FIX_CALL_DUMMY:void:fix_call_dummy:char *dummy, CORE_ADDR pc, CORE_ADDR fun,
 #
 v:2:BELIEVE_PCC_PROMOTION:int:believe_pcc_promotion::::0:::::#
 v:2:BELIEVE_PCC_PROMOTION_TYPE:int:believe_pcc_promotion_type::::0:::::#
+f:2:COERCE_FLOAT_TO_DOUBLE:int:coerce_float_to_double:struct type *formal, struct type *actual:formal, actual:::default_coerce_float_to_double
 f:1:GET_SAVED_REGISTER:void:get_saved_register:char *raw_buffer, int *optimized, CORE_ADDR *addrp, struct frame_info *frame, int regnum, enum lval_type *lval:raw_buffer, optimized, addrp, frame, regnum, lval::generic_get_saved_register:0
 #
 f:1:REGISTER_CONVERTIBLE:int:register_convertible:int nr:nr::0:0
@@ -881,7 +882,13 @@ echo "  /* basic architecture information */"
 function_list | while eval read $read
 do
   case "${class}" in
-    "i" ) echo "  ${default}," ;;
+    "i" ) 
+      if [ "${default}" = "" ]; then
+        echo "  0,"
+      else
+        echo "  ${default},"
+      fi
+    ;;
   esac
 done
 cat <<EOF
@@ -894,7 +901,13 @@ EOF
 function_list | while eval read $read
 do
   case "${class}" in
-    "f" | "v" ) echo "  ${default}," ;;
+    "f" | "v" )
+      if [ "${default}" = "" ]; then
+        echo "  0,"
+      else
+        echo "  ${default},"
+      fi
+    ;;
   esac
 done
 cat <<EOF