Add ccache support for macOS on Travis

.travis/macos/build.sh

@@ -7,8 +7,12 @@ export Qt5_DIR=$(brew --prefix)/opt/qt5
 export UNICORNDIR=$(pwd)/externals/unicorn
 
 mkdir build && cd build
+export PATH=/usr/local/opt/ccache/libexec:$PATH
+ccache --show-stats > ccache_before
 cmake --version
 cmake .. -DYUZU_BUILD_UNICORN=ON -DCMAKE_BUILD_TYPE=Release
 make -j4
+ccache --show-stats > ccache_after
+diff -U100 ccache_before ccache_after || true
 
 ctest -VV -C Release

.travis/macos/deps.sh

@@ -1,5 +1,5 @@
 #!/bin/sh -ex
 
 brew update
-brew install dylibbundler p7zip qt5 sdl2
+brew install dylibbundler p7zip qt5 sdl2 ccache
 brew outdated cmake || brew upgrade cmake