[analyzer][tests] Use normalize_plist in place of diff_plist (`cat` cases)

Summary:
The `%diff_plist` lit substitution invokes `diff` with a non-portable
`-I` option. The intended effect can be achieved by normalizing the
inputs to `diff` beforehand. Such normalization can be done with
`grep -Ev`, which is also used by other tests.

This patch applies the change (adjusted for review comments) described
in http://lists.llvm.org/pipermail/cfe-dev/2019-April/061904.html
mechanically to the cases where the output file is piped to
`%diff_plist` via `cat`.

The changes were applied via a script, except that
`clang/test/Analysis/NewDelete-path-notes.cpp` and
`clang/test/Analysis/plist-macros-with-expansion.cpp` were each adjusted
for the line-continuation on the relevant `RUN` step.

Reviewers: NoQ, sfertile, xingxue, jasonliu, daltenty

Subscribers: xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, Charusso, jsji, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D62950

llvm-svn: 362996