[CMake] Set LD_LIBRARY_PATH to builder's runtime when building stdlib
In Linux. Instead of setting temporary "fallback" RUNPATH, Set
LD_LIBRARY_PATH to builder's runtime when building standard library.
So we don't need to strip the temporary RUNPATH when installing.
(cherry picked from commit 757aaa347d288c98c2514c95e025e21c2e149f53)
(cherry picked from commit f5445f448ba26ae143f399d123dd6ef6aa586356)