Add test for R_ARC_GOTPC32 relocation.

Test the ability to resolve R_ARC_GOTPC32 relocations when we are also
linking in a shared library.  Added two tests, but they deliberately
share a single source file, the linker script places the output sections
in a different order.

ChangeLog:

	* ld/testsuite/ld-arc/arc.exp: New file.
	* ld/testsuite/ld-arc/dummy-lib.s: New file.
	* ld/testsuite/ld-arc/gotpc1.d: New file.
	* ld/testsuite/ld-arc/gotpc1.ld: New file.
	* ld/testsuite/ld-arc/gotpc1.s: New file.
	* ld/testsuite/ld-arc/gotpc2.d: New file.
	* ld/testsuite/ld-arc/gotpc2.ld: New file.