Move exception to C10 (#12354)

Summary:
There are still a few work to be done:

- Move logging and unify AT_WARN with LOG(ERROR).
- A few header files are still being plumbed through, need cleaning.
- caffe2::EnforceNotMet aliasing is not done yet.
- need to unify the macros. See c10/util/Exception.h

This is mainly a codemod and not causing functional changes. If you find your job failing and trace back to this diff, usually it can be fixed by the following approaches:

(1) add //caffe2/c10:c10 to your dependency (or transitive dependency).
(2) change objects such as at::Error, at::Optional to the c10 namespace.
(3) change functions to the c10 namespace. Especially, caffe2::MakeString is not overridden by the unified c10::str function. Nothing else changes.

Please kindly consider not reverting this diff - it involves multiple rounds of rebasing and the fix is usually simple. Contact jiayq@ or AI Platform Dev for details.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/12354

Reviewed By: orionr

Differential Revision: D10238910

Pulled By: Yangqing

fbshipit-source-id: 7794d5bf2797ab0ca6ebaccaa2f7ebbd50ff8f32

setup.py

@@ -853,7 +853,9 @@ include_dirs += [
 library_dirs.append(lib_path)
 
 # we specify exact lib names to avoid conflict with lua-torch installs
-CAFFE2_LIBS = [os.path.join(lib_path, 'libcaffe2.so')]
+CAFFE2_LIBS = [
+    os.path.join(lib_path, 'libcaffe2.so'),
+    os.path.join(lib_path, 'libc10.so')]
 if USE_CUDA:
     CAFFE2_LIBS.extend(['-Wl,--no-as-needed', os.path.join(lib_path, 'libcaffe2_gpu.so'), '-Wl,--as-needed'])
 if USE_ROCM:
@@ -877,7 +879,10 @@ if IS_DARWIN:
     NCCL_LIB = os.path.join(lib_path, 'libnccl.2.dylib')
 
 if IS_WINDOWS:
-    CAFFE2_LIBS = [os.path.join(lib_path, 'caffe2.lib')]
+    CAFFE2_LIBS = [
+        os.path.join(lib_path, 'caffe2.lib'),
+        os.path.join(lib_path, 'c10.lib')
+    ]
     if USE_CUDA:
         CAFFE2_LIBS.append(os.path.join(lib_path, 'caffe2_gpu.lib'))
     if USE_ROCM: