Compile IAMCU tests with -fno-pie -no-pie

Compile IAMCU tests with -fno-pie -no-pie

Since IAMCU tests clear all scratch integer registers with:

  asm __volatile__ ("xor %%eax, %%eax\n\t" \
                    "xor %%edx, %%edx\n\t" \
                    "xor %%ecx, %%ecx\n\t" \
                    ::: "eax", "edx", "ecx");

PIC register may be trashed between setting PIC register and using it.
This patch compiles AMCU tests with -fno-pie -no-pie.

	PR target/67110
	* gcc.target/i386/iamcu/abi-iamcu.exp (additional_flags): Add
	-fno-pie -no-pie.

From-SVN: r226570