Make target features check work with ctor and dtor-

The problem was reported in PR45468, applying target features to an
always_inline constructor/destructor runs afoul of GlobalDecl
construction assert when checking for target-feature compatibility.

The core problem is fixed by using the version of the check that takes a
FunctionDecl rather than the GlobalDecl. However, while writing the
test, I discovered that source locations weren't properly set for this
check on ctors/dtors. This patch also fixes constructors and CALLED destructors.

Unfortunately, it doesn't seem too possible to get a meaningful source
location for a 'cleanup' destructor, so those are still 'frontend' level
errors unfortunately. A fixme was added to the test to cover that
situation.