[ARM] Fix size-optimization-ieee testcase failure

On some version of dejagnu, options in RUNTESTFLAGS are appended to the
command-line and thus any -mfloat-abi=softfp or -mfloat-abi=hard in
there overwrite the -mfloat-abi=soft in the dg-options for
size-optimization-ieee-* tests. Test is still run though because
arm_soft_ok returns true if -mfloat-abi=soft is accepted, even if the
file is not compiled for softfloat due to a later -mfloat-abi on the
command line.

This patch adds a dg-skip-if to those tests to ensure they are not run
in softfp or hard mode.

2018-12-21  Thomas Preud'homme  <thomas.preudhomme@linaro.org>

    gcc/testsuite/
    * gcc.target/arm/size-optimization-ieee-1.c: Skip if passing
    -mfloat-abi=softfp or -mfloat-abi=hard.
    * gcc.target/arm/size-optimization-ieee-2.c: Likewise.
    * gcc.target/arm/size-optimization-ieee-3.c: Likewise.

From-SVN: r267323

gcc/testsuite/ChangeLog

+2018-12-21  Thomas Preud'homme  <thomas.preudhomme@linaro.org>
+
+	* gcc.target/arm/size-optimization-ieee-1.c: Skip if passing
+	-mfloat-abi=softfp or -mfloat-abi=hard.
+	* gcc.target/arm/size-optimization-ieee-2.c: Likewise.
+	* gcc.target/arm/size-optimization-ieee-3.c: Likewise.
+
 2018-12-21  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/88547

gcc/testsuite/gcc.target/arm/size-optimization-ieee-1.c

 /* { dg-do link { target arm_soft_ok } } */
+/* { dg-skip-if "Feature is -mfloat-abi=soft only" { *-*-* } { "-mfloat-abi=*" } { "-mfloat-abi=soft" } } */
 /* { dg-options "-mfloat-abi=soft" } */
 
 int

gcc/testsuite/gcc.target/arm/size-optimization-ieee-2.c

 /* { dg-do link { target arm_soft_ok } } */
+/* { dg-skip-if "Feature is -mfloat-abi=soft only" { *-*-* } { "-mfloat-abi=*" } { "-mfloat-abi=soft" } } */
 /* { dg-options "-mfloat-abi=soft" } */
 
 int

gcc/testsuite/gcc.target/arm/size-optimization-ieee-3.c

 /* { dg-do link { target arm_soft_ok } } */
+/* { dg-skip-if "Feature is -mfloat-abi=soft only" { *-*-* } { "-mfloat-abi=*" } { "-mfloat-abi=soft" } } */
 /* { dg-options "-mfloat-abi=soft" } */
 
 int