testsuite: Fix gcc.target/i386/auto-init-* tests.

This set of tests failed on many different combination of -march, -mtune.
some of them failed with -fstack-protestor-all, or -mno-sse. And the
pattern matches are also different on lp64 or ia32.

The reason for these failures is that the RTL or assembly level patten
matches are only valid for -march=x86-64 -mtune=generic.

We restrict the testing only for -march=x86-64 and -mtune=generic. Also
add -fno-stack-protector or -msse for some of the testing cases.

gcc/testsuite/ChangeLog:

2021-09-17  qing zhao  <qing.zhao@oracle.com>

	* gcc.target/i386/auto-init-1.c: Restrict the testing only for
	-march=x86-64 and -mtune=generic. Add -fno-stack-protector.
	* gcc.target/i386/auto-init-2.c: Restrict the testing only for
	-march=x86-64 and -mtune=generic -msse.
	* gcc.target/i386/auto-init-3.c: Likewise.
	* gcc.target/i386/auto-init-4.c: Likewise.
	* gcc.target/i386/auto-init-5.c: Different pattern match for lp64 and
	ia32.
	* gcc.target/i386/auto-init-6.c: Restrict the testing only for
	-march=x86-64 and -mtune-generic -msse. Add -fno-stack-protector.
	* gcc.target/i386/auto-init-7.c: Likewise.
	* gcc.target/i386/auto-init-8.c: Restrict the testing only for
	-march=x86-64 and -mtune=generic -msse..
	* gcc.target/i386/auto-init-padding-1.c: Likewise.
	* gcc.target/i386/auto-init-padding-10.c: Likewise.
	* gcc.target/i386/auto-init-padding-11.c: Likewise.
	* gcc.target/i386/auto-init-padding-12.c: Likewise.
	* gcc.target/i386/auto-init-padding-2.c: Likewise.
	* gcc.target/i386/auto-init-padding-3.c: Restrict the testing only for
	-march=x86-64. Different pattern match for lp64 and ia32.
	* gcc.target/i386/auto-init-padding-4.c: Restrict the testing only for
	-march=x86-64 and -mtune-generic -msse.
	* gcc.target/i386/auto-init-padding-5.c: Likewise.
	* gcc.target/i386/auto-init-padding-6.c: Likewise.
	* gcc.target/i386/auto-init-padding-7.c: Restrict the testing only for
	-march=x86-64 and -mtune-generic -msse. Add -fno-stack-protector.
	* gcc.target/i386/auto-init-padding-8.c: Likewise.
	* gcc.target/i386/auto-init-padding-9.c: Restrict the testing only for
	-march=x86-64. Different pattern match for lp64 and ia32.