Target FP: Add string routines to target-float.{c,h}

This adds target_float_to_string and target_float_from_string,
which dispatch to the corresponding floatformat_ or decimal_ routines.

Existing users of those routines are changed to use the new
target-float routines instead (most of those places already handle
both binary and decimal FP).

In addition, two other places are changes to use target_float_from_string:

- define_symbol in stabsread.c, when parsing a floating-point literal
  from stabs debug info

- gdbarch-selftest.c when initializing a target format values (to
  eliminate use of DOUBLEST there).

gdb/ChangeLog:
2017-11-06  Ulrich Weigand  <uweigand@de.ibm.com>

	* target-float.c (target_float_to_string): New function.
	(target_float_from_string): New function.
	* target-float.h (target_float_to_string): Add prototype.
	(target_float_from_string): Add prototype.

	* valprint.c: Include "target-float.h".  Do not include
	"doublest.h" and "dfp.h".
	(print_floating): Use target_float_to_string.
	* printcmd.c: Include "target-float.h".  Do not include "dfp.h".
	(printf_floating): Use target_float_to_string.
	* i387-tdep.c: Include "target-float.h".  Do not include "doublest.h".
	(print_i387_value): Use target_float_to_string.
	* mips-tdep.c: Include "target-float.h".
	(mips_print_fp_register): Use target_float_to_string.
	* sh64-tdep.c: Include "target-float.h".
	(sh64_do_fp_register): Use target_float_to_string.

	* parse.c: Include "target-float.h".  Do not include
	"doublest.h" and "dfp.h".
	(parse_float): Use target_float_from_string.
	* stabsread.c: Include "target-float.h".  Do not include "doublest.h".
	(define_symbol): Use target_float_from_string.
	* gdbarch-selftests.c: Include "target-float.h".
	(register_to_value_test): Use target_float_from_string.

1 files changed, 2 insertions, 4 deletions

diff --git a/gdb/gdbarch-selftests.c b/gdb/gdbarch-selftests.c
index 58ed112..c748fcc 100644
--- a/gdb/gdbarch-selftests.c
+++ b/gdb/gdbarch-selftests.c
@@ -24,6 +24,7 @@
 #include "inferior.h"
 #include "gdbthread.h"
 #include "target.h"
+#include "target-float.h"
 
 namespace selftests {
 
@@ -178,11 +179,8 @@ register_to_value_test (struct gdbarch *gdbarch)
 
 	      if (TYPE_CODE (type) == TYPE_CODE_FLT)
 		{
-		  DOUBLEST d = 1.25;
-
 		  /* Generate valid float format.  */
-		  floatformat_from_doublest (floatformat_from_type (type),
-					     &d, expected.data ());
+		  target_float_from_string (expected.data (), type, "1.25");
 		}
 	      else
 		{