x86-64: Estimate output section layout before sizing dynamic sections

x86-64: Estimate output section layout before sizing dynamic sections

When sizing dynamic sections, elf_x86_64_scan_relocs converts GOTPCREL
relocations to R_X86_64_PC32, R_X86_64_32S or R_X86_64_32 for local
symbols.  But at that time, since the output section layout is unknown,
the local symbol values can't be determined.  Later linker issues an
error if the converted relocation overflows when resolving relocations
against these local symbols.  Update the x86-64 ELF linker to estimate
output section layout before sizing dynamic sections and use the
preliminary output section layout info to skip the GOTPCREL relocation
conversion if the converted relocation overflows.

bfd/

	PR ld/32591
	* elf64-x86-64.c (elf_x86_64_convert_load_reloc): Add an input
	section argument.  Use the lowest-addressed section to estimate
	the __ehdr_start symbol value.  Don't convert relocation if the
	converted relocation will overflow.

ld/

	PR ld/32591
	* emultempl/elf-x86.em (elf_x86_64_before_allocation):
	New.  Defined for x86-64.
	(LDEMUL_BEFORE_ALLOCATION): Likewise.
	* testsuite/ld-x86-64/pr19609-2a.d: Don't fail.
	* testsuite/ld-x86-64/pr19609-2b.d: Likewise.
	* testsuite/ld-x86-64/pr19609-4a.d: Likewise.
	* testsuite/ld-x86-64/pr19609-5d.d: Likewise.
	* testsuite/ld-x86-64/pr19609-7a.d: Likewise.
	* testsuite/ld-x86-64/pr19609-7c.d: Likewise.
	* testsuite/ld-x86-64/pr32591-1.s: New file.
	* testsuite/ld-x86-64/pr32591-1a-x32.d: Likewise.
	* testsuite/ld-x86-64/pr32591-1a.d: Likewise.
	* testsuite/ld-x86-64/pr32591-1a.t: Likewise.
	* testsuite/ld-x86-64/pr32591-1b-x32.d: Likewise.
	* testsuite/ld-x86-64/pr32591-1b.d: Likewise.
	* testsuite/ld-x86-64/pr32591-1b.t: Likewise.
	* testsuite/ld-x86-64/pr32591-1c-x32.d: Likewise.
	* testsuite/ld-x86-64/pr32591-1c.d: Likewise.
	* testsuite/ld-x86-64/pr32591-1c.t: Likewise.
	* testsuite/ld-x86-64/pr32591-1d-x32.d: Likewise.
	* testsuite/ld-x86-64/pr32591-1d.d: Likewise.
	* testsuite/ld-x86-64/pr32591-1d.t: Likewise.
	* testsuite/ld-x86-64/pr32591-2.s: Likewise.
	* testsuite/ld-x86-64/pr32591-2-x32.d: Likewise.
	* testsuite/ld-x86-64/pr32591-2.d: Likewise.
	* testsuite/ld-x86-64/pr32591-2.t: Likewise.
	* testsuite/ld-x86-64/pr32591-3.s: Likewise.
	* testsuite/ld-x86-64/pr32591-3-x32.d: Likewise.
	* testsuite/ld-x86-64/pr32591-3.d: Likewise.
	* testsuite/ld-x86-64/pr32591-3.t: Likewise.
	* testsuite/ld-x86-64/pr32591-4.s: Likewise.
	* testsuite/ld-x86-64/pr32591-4-x32.d: Likewise.
	* testsuite/ld-x86-64/pr32591-4.d: Likewise.
	* testsuite/ld-x86-64/x86-64.exp: Run PR ld/32591 tests.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>