Drop o3tl::optional wrapper

...now that macOS builds are guaranteed to have std::optional since
358146bbbd1b9775c12770fb5e497b6ec5adfc51 "Bump macOS build baseline to
Xcode 11.3 and macOS 10.14.4".

The change is done mostly mechanically with

> for i in $(git grep -Fl optional); do
>  sed -i -e 's:<o3tl/optional\.hxx>\|\"o3tl/optional\.hxx\":<optional>:' \
>   -e 's/\<o3tl::optional\>/std::optional/g' \
>   -e 's/\<o3tl::make_optional\>/std::make_optional/g' "$i"
> done
> for i in $(git grep -Flw o3tl::nullopt); do
>  sed -i -e 's/\<o3tl::nullopt\>/std::nullopt/g' "$i"
> done

(though that causes some of the resulting

  #include <optional>

to appear at different places relative to other includes than if they had been
added manually), plus a few manual modifications:

* adapt bin/find-unneeded-includes
* adapt desktop/IwyuFilter_desktop.yaml
* remove include/o3tl/optional.hxx
* quote resulting "<"/">" as "&lt;"/"&gt;" in officecfg/registry/cppheader.xsl
* and then solenv/clang-format/reformat-formatted-files

Change-Id: I68833d9f7945e57aa2bc703349cbc5a56b342273
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89165
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/forms/source/component/ListBox.cxx b/forms/source/component/ListBox.cxx
index 749f10e83bc5..f33312952e44 100644
--- a/forms/source/component/ListBox.cxx
+++ b/forms/source/component/ListBox.cxx
@@ -47,7 +47,7 @@
 #include <sal/log.hxx>
 #include <unotools/sharedunocomponent.hxx>
 
-#include <o3tl/optional.hxx>
+#include <optional>
 
 #include <algorithm>
 #include <iterator>
@@ -732,7 +732,7 @@ namespace frm
             return;
         }
 
-        ::o3tl::optional< sal_Int16 > aBoundColumn(o3tl::nullopt);
+        ::std::optional< sal_Int16 > aBoundColumn(std::nullopt);
         if ( m_aBoundColumn.getValueType().getTypeClass() == TypeClass_SHORT )
         {
             sal_Int16 nBoundColumn( 0 );