RISC-V: Fix the test case bug-3.c failure

RISC-V: Fix the test case bug-3.c failure

The bug-3.c would like to check the slli a[0-9]+, a[0-9]+, 33 for the
big poly int handling.  But the underlying insn may change to slli 1
+ slli 32 with sorts of optimization.  Thus, update the asm check to
function body check with above slli 1 + slli 32 series.

The below test suites are passed for this patch.
* The rv64gcv fully regression test.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/bug-3.c: Update asm check to
	function body check.

Signed-off-by: Pan Li <pan2.li@intel.com>