elflint, readelf, support SHT_LLVM_LTO and SHT_LLVM_ADDRSIG

elflint, readelf, support SHT_LLVM_LTO and SHT_LLVM_ADDRSIG

An SHT_LLVM_LTO section contains LLVM bitcode. An SHT_LLVM_ADDRSIG
section contains ULEB128 integers referring to the symbol table
indexes of address-significant symbols. This patch just recognizes the
SHT constants but doesn't handle the section contents.

	 * libebl/eblsectiontypename.c (ebl_section_type_name):
	 Recognize SHT_LLVM_ADDRSIG and SHT_LLVM_LTO.

Signed-off-by: Mark Wielaard <mark@klomp.org>