[DebugInfo] Add DWARF emission for DBG_VALUE_LIST

This patch allows DBG_VALUE_LIST instructions to be emitted to DWARF with valid
DW_AT_locations. This change mainly affects DbgEntityHistoryCalculator, which
now tracks multiple registers per value, and DwarfDebug+DwarfExpression, which
can now emit multiple machine locations as part of a DWARF expression.

Differential Revision: https://reviews.llvm.org/D83495