PR27226, ld.bfd contains huge .rodata section

PR27226, ld.bfd contains huge .rodata section

This makes it possible to build ld without any compiled-in scripts,
by setting COMPILE_IN=no in the environment.  pe, beos and pdp11
targets didn't support scripts from the file system, with pdp11
nastily editing the ld/ldscripts file so that the built-in script
didn't match.

	PR 27226
	* emulparams/alphavms.sh: Don't set COMPILE_IN.
	* emulparams/elf64_ia64_vms.sh: Likewise.
	* emulparams/elf64mmix.sh: Likewise.
	* emulparams/elf_iamcu.sh: Likewise.
	* emulparams/elf_k1om.sh: Likewise.
	* emulparams/elf_l1om.sh: Likewise.
	* emulparams/mmo.sh: Likewise.
	* emulparams/pdp11.sh: Set DATA_SEG_ADDR.
	* scripttempl/pdp11.sc: Use it.
	* emultempl/pdp11.em: Don't edit .xn script for separate_code,
	instead use .xe script.  Support scripts from file system.
	* emultempl/beos.em: Support scripts from file system.
	* emultempl/pe.em: Likewise.
	* emultempl/pep.em: Likewise.
	* testsuite/ld-bootstrap/bootstrap.exp: Make tmpdir/ldscripts link.