Auto merge of #15099 - servo:phf-no-macros, r=jdm

Remove usage of phf_macros.

It’s a compiler plugin that uses unstable compiler APIs that are not on a path to stabilization.

With this changes, there is one less thing that might break when we update the compiler. For example: https://github.com/sfackler/rust-phf/pull/101

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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- [ ] There are tests for these changes OR
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components/script/dom/bindings/codegen/CodegenRust.py

@@ -6840,6 +6840,15 @@ class GlobalGenRoots():
         ], "\n")), pre="pub flags Globals: u8 {\n", post="\n}")
         globals_ = CGWrapper(CGIndenter(global_flags), pre="bitflags! {\n", post="\n}")
 
+        phf = CGGeneric("include!(concat!(env!(\"OUT_DIR\"), \"/InterfaceObjectMapPhf.rs\"));")
+
+        return CGList([
+            CGGeneric(AUTOGENERATED_WARNING_COMMENT),
+            CGList([imports, globals_, phf], "\n\n")
+        ])
+
+    @staticmethod
+    def InterfaceObjectMapData(config):
         pairs = []
         for d in config.getDescriptors(hasInterfaceObject=True, isInline=False):
             binding = toBindingNamespace(d.name)
@@ -6848,19 +6857,13 @@ class GlobalGenRoots():
                 pairs.append((ctor.identifier.name, binding, binding))
         pairs.sort(key=operator.itemgetter(0))
         mappings = [
-            CGGeneric('b"%s" => codegen::Bindings::%s::%s::DefineDOMInterface as unsafe fn(_, _),' % pair)
+            CGGeneric('"%s": "codegen::Bindings::%s::%s::DefineDOMInterface as unsafe fn(_, _)"' % pair)
             for pair in pairs
         ]
-        mapType = "phf::Map<&'static [u8], unsafe fn(*mut JSContext, HandleObject)>"
-        phf = CGWrapper(
-            CGIndenter(CGList(mappings, "\n")),
-            pre="pub static MAP: %s = phf_map! {\n" % mapType,
-            post="\n};\n")
-
-        return CGList([
-            CGGeneric(AUTOGENERATED_WARNING_COMMENT),
-            CGList([imports, globals_, phf], "\n\n")
-        ])
+        return CGWrapper(
+            CGList(mappings, ",\n"),
+            pre="{\n",
+            post="\n}\n")
 
     @staticmethod
     def PrototypeList(config):