match bootstrapped compiler to architecture (#14059)

lib/spack/spack/package.py

@@ -1509,6 +1509,7 @@ def bootstrap_compiler(self, **kwargs):
         )
         if not compilers:
             dep = spack.compilers.pkg_spec_for_compiler(self.spec.compiler)
+            dep.architecture = self.spec.architecture
             # concrete CompilerSpec has less info than concrete Spec
             # concretize as Spec to add that information
             dep.concretize()