Avoid inheriting formatter flags in some Display impls

The previous implementation would produce wrong unintentional output
when formatting with alignment or padding, such as {:<15}.

Author: dtolnay

gen/src/error.rs

@@ -87,12 +87,11 @@ pub(crate) fn report(error: impl StdError) -> impl Display {
 
     impl<E: StdError> Display for Report<E> {
         fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-            Display::fmt(&self.0, formatter)?;
+            write!(formatter, "{}", self.0)?;
             let mut error: &dyn StdError = &self.0;
 
             while let Some(cause) = error.source() {
-                formatter.write_str("\n\nCaused by:\n    ")?;
-                Display::fmt(cause, formatter)?;
+                write!(formatter, "\n\nCaused by:\n    {}", cause)?;
                 error = cause;
             }
 

macro/src/load.rs

@@ -308,9 +308,8 @@ struct CxxName<'a>(&'a Pair);
 impl<'a> Display for CxxName<'a> {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         for namespace in &self.0.namespace {
-            Display::fmt(namespace, formatter)?;
-            formatter.write_str("::")?;
+            write!(formatter, "{}::", namespace)?;
         }
-        Display::fmt(&self.0.cxx, formatter)
+        write!(formatter, "{}", self.0.cxx)
     }
 }

syntax/discriminant.rs

@@ -208,7 +208,7 @@ impl Display for Discriminant {
         if self.sign == Sign::Negative {
             f.write_str("-")?;
         }
-        Display::fmt(&self.magnitude, f)
+        write!(f, "{}", self.magnitude)
     }
 }