[lldb][test] Move no_unique_address to DWARF/x86

Follow up to #111902.

Makes sure all the `no_unique_address` tests are in the same
place and we don't rely on the host compiler.

Now that we don't compile with the host compiler, this patch
also adds `-c` to the compilation command since we don't actually
need the linked binary in the test anyway (and on Darwin linking
through Clang requires the `xcrun` prefix to set up the SDK paths,
etc.). We already do this in `no_unique_address-with-bitfields.cpp`
anyway.

Author: Michael137

lldb/test/Shell/SymbolFile/DWARF/no_unique_address-alignment.cpp renamed to lldb/test/Shell/SymbolFile/DWARF/x86/no_unique_address-alignment.cpp

@@ -1,6 +1,6 @@
 // XFAIL: *
 
-// RUN: %clangxx_host -gdwarf -o %t %s
+// RUN: %clang --target=x86_64-apple-macosx -c -gdwarf -o %t %s
 // RUN: %lldb %t \
 // RUN:   -o "expr alignof(OverlappingFields)" \
 // RUN:   -o "expr sizeof(OverlappingFields)" \

lldb/test/Shell/SymbolFile/DWARF/no_unique_address-base-alignment.cpp renamed to lldb/test/Shell/SymbolFile/DWARF/x86/no_unique_address-base-alignment.cpp

@@ -1,6 +1,6 @@
 // XFAIL: *
 
-// RUN: %clangxx_host -gdwarf -o %t %s
+// RUN: %clang --target=x86_64-apple-macosx -c -gdwarf -o %t %s
 // RUN: %lldb %t \
 // RUN:   -o "expr alignof(OverlappingDerived)" \
 // RUN:   -o "expr sizeof(OverlappingDerived)" \