[yaml2obj] - Do not ignore explicit addresses for .dynsym and .dynstr

This fixes https://bugs.llvm.org/show_bug.cgi?id=40339

Previously if the addresses were set in YAML they were ignored for
.dynsym and .dynstr sections. The patch fixes that.

Differential revision: https://reviews.llvm.org/D58168

llvm-svn: 354318