Merge #12097: [scripts] lint-whitespace: use perl instead of grep -P

40b17f5f9 [scripts] lint-whitespace: use perl instead of grep -P (Sjors Provoost)

Pull request description:

  MacOS does not support `grep -P` out of the box. This change makes
  it easier for developers to check for whitespace problems locally.

  Based on [this](https://stackoverflow.com/a/16658690) and [this](https://serverfault.com/a/504387) Stack Exchange answer.

  Tested with:
  ```sh
  export TRAVIS_COMMIT_RANGE='fe78c9a...62e0453'
  contrib/devtools/lint-whitespace.sh
  This diff appears to have added new lines with tab characters instead of spaces.
  The following changes were suspected:

  diff --git a/src/test/bignum_tests.cpp b/src/test/bignum_tests.cpp
  @@ -0,0 +1,110 @@
  +	num.setint64(n);
  ```

Tree-SHA512: 37c342a0ca2580289cf326a278a051a7c21ba918d6b2143fd9987f159fab85f1de3d770fcf532a642cd5d1957afc8595678128196e102dc473924758f133db7f

0 files changed, 0 insertions, 0 deletions