Fix Bug #1378022, UTF-8 files with a leading BOM crashed the interpreter.

Needs backport.
diff --git a/Lib/test/bad_coding2.py b/Lib/test/bad_coding2.py
new file mode 100644
index 0000000..604b122
--- /dev/null
+++ b/Lib/test/bad_coding2.py
@@ -0,0 +1,2 @@
+#coding: utf8

+print '我'
\ No newline at end of file