Make "missing field" error message more natural

src/test/ui/error-codes/E0063.rs

@@ -32,7 +32,7 @@ fn main() {
     let w = SingleFoo { };
     //~^ ERROR missing field `x` in initializer of `SingleFoo`
     let x = PluralFoo {x: 1};
-    //~^ ERROR missing fields `y`, `z` in initializer of `PluralFoo`
+    //~^ ERROR missing fields `y` and `z` in initializer of `PluralFoo`
     let y = TruncatedFoo{x:1};
     //~^ missing fields `a`, `b`, `y` and 1 other field in initializer of `TruncatedFoo`
     let z = TruncatedPluralFoo{x:1};

src/test/ui/error-codes/E0063.stderr

@@ -4,11 +4,11 @@ error[E0063]: missing field `x` in initializer of `SingleFoo`
 LL |     let w = SingleFoo { };
    |             ^^^^^^^^^ missing `x`
 
-error[E0063]: missing fields `y`, `z` in initializer of `PluralFoo`
+error[E0063]: missing fields `y` and `z` in initializer of `PluralFoo`
   --> $DIR/E0063.rs:34:13
    |
 LL |     let x = PluralFoo {x: 1};
-   |             ^^^^^^^^^ missing `y`, `z`
+   |             ^^^^^^^^^ missing `y` and `z`
 
 error[E0063]: missing fields `a`, `b`, `y` and 1 other field in initializer of `TruncatedFoo`
   --> $DIR/E0063.rs:36:13

src/test/ui/issues/issue-79593.rs

@@ -23,7 +23,7 @@ fn wrong() {
     foo::Enum::Variant { x: () };
     //~^ ERROR missing field `y` in initializer of `Enum`
     foo::Enum::Variant { };
-    //~^ ERROR missing fields `x`, `y` in initializer of `Enum`
+    //~^ ERROR missing fields `x` and `y` in initializer of `Enum`
 }
 
 fn main() {}

src/test/ui/issues/issue-79593.stderr

@@ -22,11 +22,11 @@ error[E0063]: missing field `y` in initializer of `Enum`
 LL |     foo::Enum::Variant { x: () };
    |     ^^^^^^^^^^^^^^^^^^ missing `y`
 
-error[E0063]: missing fields `x`, `y` in initializer of `Enum`
+error[E0063]: missing fields `x` and `y` in initializer of `Enum`
   --> $DIR/issue-79593.rs:25:5
    |
 LL |     foo::Enum::Variant { };
-   |     ^^^^^^^^^^^^^^^^^^ missing `x`, `y`
+   |     ^^^^^^^^^^^^^^^^^^ missing `x` and `y`
 
 error: aborting due to 5 previous errors
 

src/test/ui/parser/issue-52496.rs

@@ -7,6 +7,6 @@ fn main() {
     let bar = 1.5f32;
     let _ = Foo { bar.into(), bat: -1, . };
     //~^ ERROR expected one of
-    //~| ERROR missing fields `bar`, `baz` in initializer of `Foo`
+    //~| ERROR missing fields `bar` and `baz` in initializer of `Foo`
     //~| ERROR expected identifier, found `.`
 }

src/test/ui/parser/issue-52496.stderr

@@ -26,11 +26,11 @@ error[E0063]: missing field `bat` in initializer of `Foo`
 LL |     let _ = Foo { bar: .5, baz: 42 };
    |             ^^^ missing `bat`
 
-error[E0063]: missing fields `bar`, `baz` in initializer of `Foo`
+error[E0063]: missing fields `bar` and `baz` in initializer of `Foo`
   --> $DIR/issue-52496.rs:8:13
    |
 LL |     let _ = Foo { bar.into(), bat: -1, . };
-   |             ^^^ missing `bar`, `baz`
+   |             ^^^ missing `bar` and `baz`
 
 error: aborting due to 5 previous errors
 

src/test/ui/parser/struct-field-numeric-shorthand.rs

@@ -5,5 +5,5 @@ fn main() {
     //~^ ERROR expected identifier, found `0`
     //~| ERROR expected identifier, found `1`
     //~| ERROR expected identifier, found `2`
-    //~| ERROR missing fields `0`, `1`, `2` in initializer of `Rgb`
+    //~| ERROR missing fields `0`, `1` and `2` in initializer of `Rgb`
 }

src/test/ui/parser/struct-field-numeric-shorthand.stderr

@@ -22,11 +22,11 @@ LL |     let _ = Rgb { 0, 1, 2 };
    |             |
    |             while parsing this struct
 
-error[E0063]: missing fields `0`, `1`, `2` in initializer of `Rgb`
+error[E0063]: missing fields `0`, `1` and `2` in initializer of `Rgb`
   --> $DIR/struct-field-numeric-shorthand.rs:4:13
    |
 LL |     let _ = Rgb { 0, 1, 2 };
-   |             ^^^ missing `0`, `1`, `2`
+   |             ^^^ missing `0`, `1` and `2`
 
 error: aborting due to 4 previous errors