Don't convert R_X86_64_GOTPCREL if it will overflow

Don't convert R_X86_64_GOTPCREL if it will overflow

When converting "mov foo@GOTPCREL(%rip), %reg" to "lea foo(%rip), %reg"
with R_X86_64_PC32 relocation, it may overflow if the target section
is more than 2GB away.  This patch estimates distance between mov
instruction and the target section.  We convert R_X86_64_GOTPCREL to
R_X86_64_PC32 only if their distance is less than 2GB.

	PR ld/18591
	* elf64-x86-64.c (elf_x86_64_convert_mov_to_lea): Don't convert
	R_X86_64_GOTPCREL to R_X86_64_PC32 if it will cause relocation
	overflow.