Fix "make arm asan=$CLANG"

Bonus cleanup: remove a few duplicate compiler flags

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/220883003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20402 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Makefile

@@ -140,9 +140,9 @@ endif
 # asan=/path/to/clang++
 ifneq ($(strip $(asan)),)
   GYPFLAGS += -Dasan=1
-  export CXX="$(asan)"
-  export CXX_host="$(asan)"
-  export LINK="$(asan)"
+  export CXX=$(asan)
+  export CXX_host=$(asan)
+  export LINK=$(asan)
   export ASAN_SYMBOLIZER_PATH="$(dir $(asan))llvm-symbolizer"
 endif
 

build/toolchain.gypi

@@ -521,10 +521,7 @@
         'conditions': [
           ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd" or \
             OS=="qnx"', {
-            'cflags': [ '-Wall', '<(werror)', '-W', '-Wno-unused-parameter',
-                        '-Wnon-virtual-dtor', '-Woverloaded-virtual',
-                        '<(wno_array_bounds)',
-                      ],
+            'cflags': [ '-Woverloaded-virtual', '<(wno_array_bounds)', ],
             'conditions': [
               ['v8_optimized_debug==0', {
                 'cflags!': [