[11.9] Revert "Remove HipChat integration from GitLab"

See merge request gitlab-org/gitlab-ce!27257

Disable method instrumentation for diffs

Closes #52898

See merge request gitlab-org/gitlab-ce!27235

(cherry picked from commit b9e6e72501173c29a30ee1b4a2afb9ee9d3b1117)

b397ad8a Disable method instrumentation for diffs

Improve performance of PR import

See merge request gitlab-org/gitlab-ce!27121

(cherry picked from commit f15caf0109998308e7f960baaa541d73be8bcacb)

f3ad51f8 Improve performance of PR import

Allow to use untrusted ruby syntax

See merge request gitlab-org/gitlab-ce!26905

(cherry picked from commit 7dcc3003119666c75a35c27d73ffb297c696fcc8)

9bc4fbf1 Allow to use untrusted Regexp via feature flag

Fix MergeRequest#has_commits? nil comparison

Closes #59547

See merge request gitlab-org/gitlab-ce!26828

(cherry picked from commit b224efe767e4f8e24b51b87753f55bf6d3129f68)

6645b825 Fix MergeRequest#commits_count nil comparison

Consider array params on rendering MR list on dashboard

See merge request gitlab-org/gitlab-ce!26623

(cherry picked from commit 7926384ff32b9ad8833dcfffc9bb87d036c4bd21)

b3f5413a Consider array params on rendering MR list on dashboard

Add documentation for Google Secure LDAP

See merge request gitlab-org/gitlab-ce!26064

(cherry picked from commit 13ace389787f21b847ca09eccc194c3b08a7ea86)

1a0856ea Add documentation for Google Secure LDAP

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