FindMatlab: Avoid if() auto-dereference in 64-bit host detection
If the value of CMAKE_HOST_SYSTEM_PROCESSOR
also happens to be set as
a variable by a project (e.g. AMD64
), allowing if()
to
auto-dereference is unlikely to produce a value that matches "64".
Instead let if()
auto-dereference CMAKE_HOST_SYSTEM_PROCESSOR
.
Fixes: #17460 (closed)