use <[u8]>::escape_ascii instead of core::ascii::escape_default

compiler/rustc_middle/src/mir/mod.rs

@@ -2643,15 +2643,7 @@ fn pretty_print_const<'tcx>(
 }
 
 fn pretty_print_byte_str(fmt: &mut Formatter<'_>, byte_str: &[u8]) -> fmt::Result {
-    fmt.write_str("b\"")?;
-    for &c in byte_str {
-        for e in std::ascii::escape_default(c) {
-            fmt.write_char(e as char)?;
-        }
-    }
-    fmt.write_str("\"")?;
-
-    Ok(())
+    write!(fmt, "b\"{}\"", byte_str.escape_ascii())
 }
 
 fn comma_sep<'tcx>(fmt: &mut Formatter<'_>, elems: Vec<ConstantKind<'tcx>>) -> fmt::Result {

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -1401,14 +1401,7 @@ pub trait PrettyPrinter<'tcx>:
     }
 
     fn pretty_print_byte_str(mut self, byte_str: &'tcx [u8]) -> Result<Self::Const, Self::Error> {
-        define_scoped_cx!(self);
-        p!("b\"");
-        for &c in byte_str {
-            for e in std::ascii::escape_default(c) {
-                self.write_char(e as char)?;
-            }
-        }
-        p!("\"");
+        write!(self, "b\"{}\"", byte_str.escape_ascii())?;
         Ok(self)
     }