Rollup merge of rust-lang#5420 - dtolnay:newret, r=flip1995

Downgrade new_ret_no_self to pedantic

As motivated by rust-lang#5418. This is the second most widely suppressed Clippy style lint, and [this grep.app search](https://grep.app/search?q=%5C%5Ballow%5C%28.%2Aclippy%3A%3Anew_ret_no_self%5Cb&regexp=true&case=true&filter[lang][0]=Rust) shows a large number of diverse reasonable signatures for a `new` method.

changelog: Remove new_ret_no_self from default set of enabled lints

clippy_lints/src/lib.rs

@@ -1115,6 +1115,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&methods::FIND_MAP),
         LintId::of(&methods::INEFFICIENT_TO_STRING),
         LintId::of(&methods::MAP_FLATTEN),
+        LintId::of(&methods::NEW_RET_NO_SELF),
         LintId::of(&methods::OPTION_MAP_UNWRAP_OR),
         LintId::of(&methods::OPTION_MAP_UNWRAP_OR_ELSE),
         LintId::of(&methods::RESULT_MAP_UNWRAP_OR_ELSE),
@@ -1276,7 +1277,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&methods::ITER_NTH_ZERO),
         LintId::of(&methods::ITER_SKIP_NEXT),
         LintId::of(&methods::MANUAL_SATURATING_ARITHMETIC),
-        LintId::of(&methods::NEW_RET_NO_SELF),
         LintId::of(&methods::OK_EXPECT),
         LintId::of(&methods::OPTION_AND_THEN_SOME),
         LintId::of(&methods::OPTION_AS_REF_DEREF),
@@ -1457,7 +1457,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&methods::ITER_NTH_ZERO),
         LintId::of(&methods::ITER_SKIP_NEXT),
         LintId::of(&methods::MANUAL_SATURATING_ARITHMETIC),
-        LintId::of(&methods::NEW_RET_NO_SELF),
         LintId::of(&methods::OK_EXPECT),
         LintId::of(&methods::OPTION_MAP_OR_NONE),
         LintId::of(&methods::RESULT_MAP_OR_INTO_OPTION),

clippy_lints/src/methods/mod.rs

@@ -747,7 +747,7 @@ declare_clippy_lint! {
     /// }
     /// ```
     pub NEW_RET_NO_SELF,
-    style,
+    pedantic,
     "not returning `Self` in a `new` method"
 }
 

src/lintlist/mod.rs

@@ -1447,7 +1447,7 @@ pub static ref ALL_LINTS: Vec<Lint> = vec![
     },
     Lint {
         name: "new_ret_no_self",
-        group: "style",
+        group: "pedantic",
         desc: "not returning `Self` in a `new` method",
         deprecation: None,
         module: "methods",