[AIX][TLS][clang]  Add -maix-small-local-dynamic-tls clang option (#88829)

This patch adds the clang portion of an AIX-specific option to inform
the
compiler that it can use a faster access sequence for the local-dynamic
TLS model (formally named aix-small-local-dynamic-tls).

This patch mainly references Amy's work on small local-exec TLS support.

GitOrigin-RevId: 16efd2a4c4b6a811688e5f623cb04dbd2d0579e8
7 files changed