Update dir names to match prebuilts.

Changed the output directories to match those used in prebuilts (and
by extension, upload-toolchain and download-toolchain).

Change-Id: Id91adb6fef7ad381edc3e4e937e1d1adfd04e36d
diff --git a/do-build b/do-build
index ab02aff..e26ae1a 100755
--- a/do-build
+++ b/do-build
@@ -409,15 +409,26 @@
   fi
 }
 
+# Determine where the tools will be installed.
 get_install_dir()
 {
+  canonicalize_target_name "$TARGET"
+  local normalized_target="$RESULT"
+
   get_component_attribute "gcc" "VER"
   local gcc_ver="$RESULT"
+
   if [ "$HOST" == "$TARGET" ]
   then
-    RESULT="$OUT_DIR/gcc-${gcc_ver}_${HOST}"
+    RESULT="$OUT_DIR/$normalized_target-$gcc_ver-native"
   else
-    RESULT="$OUT_DIR/gcc-${gcc_ver}_${HOST}_to_${TARGET}"
+    canonicalize_target_name "$HOST"
+    local normalized_host="$RESULT"
+    split_arch_os "$normalized_host"
+    local normalized_host_arch="$RESULT_ARCH"
+    # The output dir has an uppercase OS name.
+    local normalized_host_os="$(echo ${RESULT_OS:0:1} | tr '[:lower:]' '[:upper:]')${RESULT_OS:1}"
+    RESULT="$OUT_DIR/$normalized_target-$gcc_ver-$normalized_host_os-$normalized_host_arch"
   fi
 }