Remove rule prohibiting including src/v8.h

src/DEPS

 include_rules = [
   "+base/trace_event/common/trace_event_common.h",
   "+src",
   "-src/compiler",
   "+src/compiler/pipeline.h",
   "+src/compiler/code-stub-assembler.h",
   "+src/compiler/wasm-compiler.h",
   "-src/heap",
   "+src/heap/heap.h",
   "+src/heap/heap-inl.h",
   "-src/interpreter",
   "+src/interpreter/bytecode-array-iterator.h",
   "+src/interpreter/bytecodes.h",
   "+src/interpreter/interpreter.h",
   "-src/libplatform",
   "-include/libplatform"
 ]
 
 specific_include_rules = {
-  ".*\.h": [
-    # Note that src/v8.h by now is a regular header file, it doesn't provide
-    # any special declarations besides the V8 class. There should be no need
-    # for including it in any .h files though. This rule is just a reminder,
-    # and can be removed once the dust has settled.
-    "-src/v8.h",
-  ],
   "d8\.cc": [
     "+include/libplatform/libplatform.h",
   ],
   "api-experimental\.cc": [
     "+src/compiler/fast-accessor-assembler.h",
   ],
 }