Build assembly files with AMBuild. (#481)

* Remove prebuilt nasm-generated object files from the tree, and use AMBuild to compile them.

* Add commands in VS project to build the object files

* Rename elf to elf32 for consistency

.travis.yml

@@ -8,6 +8,7 @@ addons:
     - linux-libc-dev
     - gcc-multilib
     - g++-multilib
+    - nasm
     sources:
     - llvm-toolchain-precise-3.7
     - ubuntu-toolchain-r-test
@@ -23,4 +24,4 @@ script:
   - mkdir build && cd build
   - PATH="~/.local/bin:$PATH"
   - CC=clang-3.7 CXX=clang-3.7 python ../configure.py --enable-optimize
-  - ambuild
+  - ambuild