de-anon for kernel is done.

We no longer need -fplan9-extensions for the kernel.

Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>

build.json

@@ -12,7 +12,7 @@
 			"/sys/src/cmd",
 			"/sys/src/games/games.json",
 			"/acme/build.json",
-			"/sys/src/9/amd64/amd64cpu.json",
+			"/sys/src/9/amd64",
 			"/sys/src/regress"
 		]
 	},

sys/src/9/amd64/inith.json

@@ -8,7 +8,6 @@
 			"-Wno-unknown-pragmas",
 			"-O0",
 			"-static",
-			"-fplan9-extensions",
 			"-mno-red-zone",
 			"-ffreestanding",
 			"-fno-builtin",