Lunch: don't use a toolchain that doesn't exist.

"lunch sdk-eng" on cygwin tries to use a gcc.exe from the
prebuild arm toolchain, but it doesn't exist. This prevents
from setting variables to point on a gcc toolchain if there
is none for the given arch.

Change-Id: I3b72220663687f9fdaacc050899aef00632f2c3c

envsetup.sh

@@ -95,18 +95,27 @@ function setpaths()
     #                                                                #
     ##################################################################
 
+    # Note: on windows/cygwin, ANDROID_BUILD_PATHS will contain spaces
+    # due to "C:\Program Files" being in the path.
+
     # out with the old
-    if [ -n $ANDROID_BUILD_PATHS ] ; then
+    if [ -n "$ANDROID_BUILD_PATHS" ] ; then
         export PATH=${PATH/$ANDROID_BUILD_PATHS/}
     fi
-    if [ -n $ANDROID_PRE_BUILD_PATHS ] ; then
+    if [ -n "$ANDROID_PRE_BUILD_PATHS" ] ; then
         export PATH=${PATH/$ANDROID_PRE_BUILD_PATHS/}
     fi
 
     # and in with the new
     CODE_REVIEWS=
     prebuiltdir=$(getprebuilt)
-    export ANDROID_EABI_TOOLCHAIN=$prebuiltdir/toolchain/arm-eabi-4.4.3/bin
+    toolchaindir=toolchain/arm-eabi-4.4.3/bin
+    # The gcc toolchain does not exists for windows/cygwin. In this case, do not reference it.
+    if [ -d "$prebuiltdir/$toolchaindir" ]; then
+        export ANDROID_EABI_TOOLCHAIN=$prebuiltdir/$toolchaindir
+    else
+        export ANDROID_EABI_TOOLCHAIN=
+    fi
     export ANDROID_TOOLCHAIN=$ANDROID_EABI_TOOLCHAIN
     export ANDROID_QTOOLS=$T/development/emulator/qtools
     export ANDROID_BUILD_PATHS=:$(get_build_var ANDROID_BUILD_PATHS):$ANDROID_QTOOLS:$ANDROID_TOOLCHAIN:$ANDROID_EABI_TOOLCHAIN$CODE_REVIEWS