Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1672 https://github.com/abseil/abseil-cpp/discussions/1671 Merge ddcbb2466b2c9c4048d60be7e58cf47f935c257d into eba8db7b Merging this change closes #1672 COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1672 from MBkkt:optimize-str-join ddcbb2466b2c9c4048d60be7e58cf47f935c257d PiperOrigin-RevId: 633988391 Change-Id: I2b3904211a29de3a768fb90a7fc106d7ff6c03e7
