php: Unify the usage of the php package in php-packages.nix

Instead of using two different php packages in php-packages.nix, one
wrapper and one unwrapped, simply use the wrapper and use its
"unwrapped" attribute when necessary. Also, get rid of the packages
and extensions attributes from the base package, since they're no
longer needed.

pkgs/development/interpreters/php/default.nix

@@ -14,8 +14,6 @@ let
     , sha256
     , extraPatches ? []
 
-    , defaultPhpExtensions
-
     # Sapi flags
     , cgiSupport ? true
     , cliSupport ? true
@@ -35,13 +33,6 @@ let
     , ztsSupport ? apxs2Support
     }@args:
       let
-        self = generic args;
-
-        php-packages = (callPackage ../../../top-level/php-packages.nix {
-          php = self;
-          phpWithExtensions = self.withExtensions defaultPhpExtensions;
-        });
-
         # buildEnv wraps php to provide additional extensions and
         # configuration. Its usage is documented in
         # doc/languages-frameworks/php.section.md.
@@ -58,7 +49,7 @@ let
               php = generic filteredArgs;
 
               php-packages = (callPackage ../../../top-level/php-packages.nix {
-                inherit php phpWithExtensions;
+                php = phpWithExtensions;
               });
 
               allExtensionFunctions = prevExtensionFunctions ++ [ extensions ];
@@ -249,7 +240,6 @@ let
           passthru = {
             buildEnv = mkBuildEnv {} [];
             withExtensions = mkWithExtensions {} [];
-            inherit (php-packages) packages extensions;
           };
 
           meta = with stdenv.lib; {
@@ -265,7 +255,6 @@ let
   php72base = callPackage generic (_args // {
     version = "7.2.29";
     sha256 = "08xry2fgqgg8s0ym1hh11wkbr36av3zq1bn4krbciw1b7x8gb8ga";
-    defaultPhpExtensions = defaultPhpExtensionsWithHash;
 
     # https://bugs.php.net/bug.php?id=76826
     extraPatches = lib.optional stdenv.isDarwin ./php72-darwin-isfinite.patch;
@@ -274,7 +263,6 @@ let
   php73base = callPackage generic (_args // {
     version = "7.3.16";
     sha256 = "0bh499v9dfgh9k51w4rird1slb9rh9whp5h37fb84c98d992s1xq";
-    defaultPhpExtensions = defaultPhpExtensionsWithHash;
 
     # https://bugs.php.net/bug.php?id=76826
     extraPatches = lib.optional stdenv.isDarwin ./php73-darwin-isfinite.patch;
@@ -283,7 +271,6 @@ let
   php74base = callPackage generic (_args // {
     version = "7.4.4";
     sha256 = "17w2m4phhpj76x5fx67vgjrlkcczqvky3f5in1kjg2pch90qz3ih";
-    inherit defaultPhpExtensions;
   });
 
   defaultPhpExtensions = { all, ... }: with all; ([