Add sancov support for large AArch64 binaries. (#185374)
In AArch64 calls have a +/-128MB range
(https://developer.arm.com/documentation/ddi0602/2025-12/Base-Instructions/BL--Branch-with-link-).
In cases where the .text is larger than that, the linker adds functions
that just jumps to the sanitizer functions and places them to some code
location where the rest of the binary can call it. These functions have
the prefix __AArch64ADRPThunk__.
This commit marks calls to this function as coverage points.
