Currently, `DynamicLoaderPOSIXDYLD::GetThreadLocalData()` only supports
the TLS memory layout where the thread pointer register points to the
start of the `pthread` structure, and the address of the DTV pointer can
be calculated by adding the offset of the `dtv` field to `tp`. On ARM
(and AArch64), the thread pointer points directly to `dtv`. The patch
improves the detection of the actual memory layout in the method and
adjusts the calculations for the new case, thus adding support for
thread-local variables on ARM Linux.
a4d786630c