Fix spec test failures introduced by recent commits.

osh/cmd_parse.py

@@ -636,7 +636,7 @@ def ParseSimpleCommand(self):
      if prefix_bindings:  # FOO=bar local spam=eggs not allowed
        # Use the location of the first value.  TODO: Use the whole word before
        # splitting.
        _, v0, _ = prefix_bindings[0]
        _, _, v0, _ = prefix_bindings[0]
        self.AddErrorContext(
            'Invalid prefix bindings in control flow: %s', prefix_bindings,
            word=v0)

spec/loop.test.sh

@@ -110,7 +110,7 @@ echo $i

### while in pipe with subshell
i=0
find . -maxdepth 1 -name INSTALL -o -name LICENSE | ( while read path; do
find . -maxdepth 1 -name INSTALL.txt -o -name LICENSE.txt | ( while read path; do
  i=$((i+1))
  #echo $i
done