[binutils-gdb] S390: Use soft float in s390-tdbregs test case

[sergiodj+buildbot at sergiodj dot net]

*** TEST RESULTS FOR COMMIT 25d4fd80936744adfa49f133524e3f342604a1cb ***

Author: Andreas Arnez <arnez@linux.vnet.ibm.com>
Branch: master
Commit: 25d4fd80936744adfa49f133524e3f342604a1cb

S390: Use soft float in s390-tdbregs test case

The GDB test case s390-tdbregs.exp verifies GDB's handling of the
"transaction diagnostic block".  For simplicity, the test case uses the
"transaction begin" (TBEGIN) instruction with the "allow floating-point
operation" flag set to zero.  But some GCC versions may indeed emit
floating point or vector instructions for this test case.  If this happens
in the transaction, it aborts, and an endless loop results.

This change tells the compiler to produce a soft-float binary, so no
floating-point or vector registers are touched.

gdb/testsuite/ChangeLog:

	* gdb.arch/s390-tdbregs.exp: Add the compile option -msoft-float.