Enabled install when building with emscripten. (#906)
Enabled install when building with emscripten. (#906)

* Enabled install when building with emscripten.

* Also install the pkg-config files.
google/brotli,google/brotli,google/brotli,google/brotli,google/brotli,google/brotli,google/brotli,google/brotli