Previously we could round-trip type records from PDB -> Yaml ->
PDB, but for symbols we could only go from PDB -> Yaml. This
completes the round-tripping for symbols as well.
llvm-svn: 297625
This is the 3rd of 3 patches to get reading and writing of
CodeView symbol and type records to use a single codepath.
Differential Revision: https://reviews.llvm.org/D26427
llvm-svn: 289978