Add dg-require-effective-target fpic to gcc i386 tests

Add dg-require-effective-target fpic to gcc i386 tests

This change adds

 /* { dg-require-effective-target fpic } */

to tests in gcc.target/i386 that do use -fpic or -fPIC
but don't currently query the target support.

This corresponds to what many other fpic tests do
and helps the vxWorks ports at least, as -fpic is
typically not supported in at least one of the two
major modes of such port (kernel vs RTP).

2020-11-03  Olivier Hainque  <hainque@adacore.com>

gcc/testsuite/

	* gcc.target/i386/pr45352-1.c: Add dg-require-effective-target fpic.
	* gcc.target/i386/pr47602.c: Likewise.
	* gcc.target/i386/pr55151.c: Likewise.
	* gcc.target/i386/pr55458.c: Likewise.
	* gcc.target/i386/pr56348.c: Likewise.
	* gcc.target/i386/pr57097.c: Likewise.
	* gcc.target/i386/pr65753.c: Likewise.
	* gcc.target/i386/pr65915.c: Likewise.
	* gcc.target/i386/pr66232-5.c: Likewise.
	* gcc.target/i386/pr66334.c: Likewise.
	* gcc.target/i386/pr66819-2.c: Likewise.
	* gcc.target/i386/pr67265.c: Likewise.
	* gcc.target/i386/pr81481.c: Likewise.
	* gcc.target/i386/pr83994.c: Likewise.