Re-land "Emit proper CodeView when -gcodeview is passed without the cl driver."
Reverts r326116 and re-lands r326113 with a fix to ASan so that it
enables column info in its test suite.
@@ -37,7 +37,11 @@ if compiler_id == "Clang":
# reports and stack traces even with minimal debug info.
config.debug_info_flags = ["-gline-tables-only"]
if platform.system() == 'Windows':
+ # On Windows, use CodeView with column info instead of DWARF. Both VS and
+ # windbg do not behave well when column info is enabled, but users have
+ # requested it because it makes ASan reports more precise.
config.debug_info_flags.append("-gcodeview")
+ config.debug_info_flags.append("-gcolumn-info")
elif compiler_id == 'GNU':
config.cxx_mode_flags = ["-x c++"]
config.debug_info_flags = ["-g"]
