Small improvements to (a|u)strings.inc.
This patch: [astr.patch](/uploads/b89afc8ca1f79c83c4c3766cc841011f/astr.patch) Slightly improves several string functions. `fpc_AnsiStr_Unique` saves two memory reads. ![ansistr_unique](/uploads/45494353e7b833f3ec8b62adb809cd16/ansistr_unique.png) `fpc_AnsiStr_Copy` saves some code and branches. ![ansistr_copy](/uploads/a908fd45821336092644f4d484a520b2/ansistr_copy.png) `fpc_AnsiStr_SetLength` changes signed `div 2` to unsigned. ![ansistr_setlength](/uploads/5ef5ae9b5f7e1ad0dd752af8e5959cf6/ansistr_setlength.png) Same for `UnicodeStr`.
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