C++: Update for EDG 6.0 behaviour change
C++: Update for EDG 6.0 behaviour change

EDG 6.0 has changed how much information it gives about invalid
expressions.  Changing the output of this test.

github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql