add build script.

Change-Id: I43f62f5646efc5bd2a7d34075bc9f94e4fea56fa
diff --git a/build.sh b/build.sh
new file mode 100755
index 0000000..e87e30c
--- /dev/null
+++ b/build.sh
@@ -0,0 +1,10 @@
+ROOT=$(pwd)
+export PATH=$PATH:$ROOT/clang/bin
+
+#ln -s external/clang llvm/tools/clang
+#ln -s external/lldb llvm/tools/lldb
+
+mkdir -p out
+cd out
+cmake -GNinja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_LINKER=ld.gold -DCMAKE_BUILD_TYPE=Debug ../external/llvm
+ninja