Add an ImageSymbol class to the PDB writer.

Add an ImageSymbol class to the PDB writer.

An ImageSymbol can write to the PDB symbol record stream a symbol that
associates a name and a type with a location in an image.

The symbol type must be one of S_LDATA32, S_GDATA32, S_PUB32,
S_LMANDATA or S_GMANDATA.

BUG=
R=chrisha@chromium.org, sebmarchand@chromium.org

Committed: https://code.google.com/p/sawbuck/source/detail?r=2227

[fdoray, 2014-08-04 21:42:36]

Could you review this CL?
Thanks.

https://codereview.appspot.com/120970044/diff/20001/syzygy/experimental/pdb_w...
File syzygy/experimental/pdb_writer/image_symbol.h (right):

https://codereview.appspot.com/120970044/diff/20001/syzygy/experimental/pdb_w...
syzygy/experimental/pdb_writer/image_symbol.h:44: const std::string& name()
const { return name_; }
I provided these 2 accessors because they are required to generate the "public"
stream.

[chrisha, 2014-08-05 13:18:30]

In keeping with our layout elsewhere in the project, can you create a 'symbols'
subdirectory, and place all concrete implementations of symbols there?

[fdoray, 2014-08-05 13:50:27]

Done.
Could you take another look? Thanks.

[Sébastien Marchand, 2014-08-05 14:22:46]

lgtm.

[chrisha, 2014-08-05 14:44:11]

lgtm with nits

https://codereview.appspot.com/120970044/diff/40001/syzygy/experimental/pdb_w...
File syzygy/experimental/pdb_writer/symbols/image_symbol.h (right):

https://codereview.appspot.com/120970044/diff/40001/syzygy/experimental/pdb_w...
syzygy/experimental/pdb_writer/symbols/image_symbol.h:13: // limitations under
the License.
High level description, please.

https://codereview.appspot.com/120970044/diff/40001/syzygy/experimental/pdb_w...
syzygy/experimental/pdb_writer/symbols/image_symbol.h:23: namespace pdb {
Add a second namespace to reflect the 'symbols' subdirectory.

[fdoray, 2014-08-05 15:24:10]

https://codereview.appspot.com/120970044/diff/40001/syzygy/experimental/pdb_w...
File syzygy/experimental/pdb_writer/symbols/image_symbol.h (right):

https://codereview.appspot.com/120970044/diff/40001/syzygy/experimental/pdb_w...
syzygy/experimental/pdb_writer/symbols/image_symbol.h:13: // limitations under
the License.
On 2014/08/05 14:44:11, chrisha wrote:
> High level description, please.

Done.

https://codereview.appspot.com/120970044/diff/40001/syzygy/experimental/pdb_w...
syzygy/experimental/pdb_writer/symbols/image_symbol.h:23: namespace pdb {
On 2014/08/05 14:44:11, chrisha wrote:
> Add a second namespace to reflect the 'symbols' subdirectory.

Done.

[fdoray, 2014-08-05 15:25:11]

Committed patchset #4 manually as 2227.