[X86] Fix missing ByValTemporaries update in CopyViaTemp path for musttail calls (#190540)
This fixes a miscompilation in musttail calls with byval arguments on
X86.
In the CopyViaTemp path, a temporary stack object is created and the
argument is copied into it.
However, the temporary is not recorded in ByValTemporaries,
so the final lowering phase does not emit the copy to the real outgoing
argument slot.
As a result, the callee may read incorrect values from the stack.
Fix this by recording the temporary in ByValTemporaries so that the
final lowering step correctly copies the argument to the expected stack
location.
Reproducer: https://github.com/llvm/llvm-project/issues/190429
[Hexagon] Add sanitizer-aware library paths for Linux/musl targets (#190267)
When compiling with -fsanitize=memory or -fsanitize=address on
hexagon-unknown-linux-musl, the driver now prepends sanitizer-specific
library paths (e.g. $SYSROOT/usr/lib/msan/) before the normal
$SYSROOT/usr/lib/ so that instrumented libraries (libc, libc++, etc.)
are found first by the linker.