appveyor: Use gist to post disassembly

appveyor.yml

@@ -7,6 +7,7 @@ install:
   - ps: Start-FileDownload "https://static.rust-lang.org/dist/rust-nightly-${env:TARGET}.exe"
   - rust-nightly-%TARGET%.exe /VERYSILENT /NORESTART /DIR="C:\Program Files (x86)\Rust"
   - SET PATH=%PATH%;C:\Program Files (x86)\Rust\bin
+  - gem install gist
   - rustc -Vv
   - cargo -V
 
@@ -17,8 +18,12 @@ test_script:
   - cargo build --release
   - cargo test
   - cargo test --release
-  - CALL "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat"
-  - dumpbin /disasm target/release/librustc_builtins.rlib || exit 0
+
+on_success:
+  - cmd: |
+    CALL "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat"
+    dumpbin /disasm target/release/librustc_builtins.rlib |
+    gist -d "'%TARGET%/rustc-builtins.rlib' from commit '%APPVEYOR_REPO_COMMIT%' on branch '%APPVEYOR_REPO_branch%'"
 
 branches:
   only: