[ur] optimize align allocation in DisjointPool #1640

Job	Run time
Build - Windows (windows-2019, Debug)	8m 37s
Build - Windows (windows-2019, Release)	13m 5s
Build - Windows (windows-2022, Debug)	11m 59s
Build - Windows (windows-2022, Release)	55m 16s
Build - Ubuntu (ubuntu-20.04, Debug, gcc, g++, -DVAL_USE_LIBBACKTRACE_BACKTRACE=OFF)	6m 28s
Build - Ubuntu (ubuntu-20.04, Release, gcc, g++, -DVAL_USE_LIBBACKTRACE_BACKTRACE=OFF)	5m 39s
Build - Ubuntu (ubuntu-22.04, Debug, gcc, g++, -DVAL_USE_LIBBACKTRACE_BACKTRACE=OFF)	6m 13s
Build - Ubuntu (ubuntu-22.04, Release, gcc, g++, -DVAL_USE_LIBBACKTRACE_BACKTRACE=OFF)	6m 55s
Build - Ubuntu (ubuntu-22.04, Release, clang, clang++, -DVAL_USE_LIBBACKTRACE_BACKTRACE=OFF)	6m 35s
Build - Ubuntu (ubuntu-22.04, Release, gcc, g++, -DVAL_USE_LIBBACKTRACE_BACKTRACE=ON)	7m 44s
Build - Ubuntu (ubuntu-22.04, Release, clang, clang++, -DVAL_USE_LIBBACKTRACE_BACKTRACE=ON)	5m 42s
Build - Ubuntu (ubuntu-20.04, Release, gcc-7, g++-7)	6m 45s
	2h 20m 58s

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