Linux: add GYP flag for -fno-strict-aliasing.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 99025df490bb71d0d84357943e078aeec1476252..fed9d962223dcd7b156f2a27d469b70a7f3c5583 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -354,6 +354,7 @@
         # be disabled in ~/.gyp/include.gypi on the valgrind builders.
         'variables': {
           'werror%': '-Werror',
+          'no_strict_aliasing%': 0,
         },
         'cflags': [
           '<(werror)',  # See note above about the werror variable.
@@ -539,6 +540,11 @@
               }],
             ],
           }],
+          ['no_strict_aliasing==1', {
+            'cflags': [
+              '-fno-strict-aliasing',
+            ],
+          }],
         ],
       },
     }],