commit 7e5649156720ec6c3aa5e2036b27811bc8195ab9
author Tom de Vries <tdevries@suse.de> Tue Oct 17 11:38:06 2023 +0200
committer Tom de Vries <tdevries@suse.de> Tue Oct 17 11:38:06 2023 +0200
tree dd39720a56af95be020e6aea1b393377e1465bdf
parent 3233ad1e4e44530fa1088cef4790bdab6ee14944

[gdb/cli] Skip string copy in source_cache::ensure

In function source_cache::ensure we have:
...
 	      std::ostringstream output;
	      ...
	      contents = output.str ();
...
The last line causes an unnecessary string copy.

C++20 allows us to skip it, like this:
...
	      contents = std::move (output).str ();
...

Use the more efficient solution.

Tested on x86_64-linux.

Reviewed-By: Lancelot Six <lancelot.six@amd.com>