fixup: spec copies compiler annotation

Signed-off-by: Massimiliano Culpo <massimiliano.culpo@gmail.com>

lib/spack/spack/spec.py

@@ -3544,6 +3544,10 @@ def _dup(self, other, deps: Union[bool, dt.DepTypes, dt.DepFlag] = True, clearde
         if cleardeps:
             self._dependents = _EdgeMap(store_by_child=False)
             self._dependencies = _EdgeMap(store_by_child=True)
+
+        if hasattr(other, "compiler_annotation"):
+            self.compiler_annotation = other.compiler_annotation
+
         self.compiler_flags = other.compiler_flags.copy()
         self.compiler_flags.spec = self
         self.variants = other.variants.copy()