extract_utils: support merging multiple blob fixups

Change-Id: I3a029cf3f8414271926a1ee8abec7d8048c51eb2

Author: luk1337

extract_utils/fixups.py

@@ -29,10 +29,16 @@ def flatten_fixups(
 
     for entries, value in fixups.items():
         if isinstance(entries, str):
-            fixups_final[entries] = value
+            if entries in fixups_final:
+                fixups_final[entries].merge(value)
+            else:
+                fixups_final[entries] = value
         else:
             assert isinstance(entries, tuple)
             for entry in entries:
-                fixups_final[entry] = value
+                if entry in fixups_final:
+                    fixups_final[entry].merge(value)
+                else:
+                    fixups_final[entry] = value
 
     return fixups_final

extract_utils/fixups_blob.py

@@ -83,6 +83,10 @@ def call(
             self.__create_tmp_dir = True
         return self
 
+    def merge(self, other: blob_fixup):
+        self.__functions += other.__functions
+        self.__create_tmp_dir = self.__create_tmp_dir or other.__create_tmp_dir
+
     def patchelf_version(self, version: str) -> blob_fixup:
         self.__patchelf_path = patchelf_version_path_map[version]
         return self