Adjust according to estebank's review comments

src/librustc_parse/parser/stmt.rs

@@ -174,7 +174,10 @@ impl<'a> Parser<'a> {
         } else {
             (None, None)
         };
-        let init = match (self.parse_initializer(let_span, ty.is_some(), err.is_some()), err) {
+        let init = match (
+            self.parse_initializer(let_span.until(pat.span), ty.is_some(), err.is_some()),
+            err,
+        ) {
             (Ok(init), None) => {
                 // init parsed, ty parsed
                 init
@@ -231,25 +234,19 @@ impl<'a> Parser<'a> {
                 self.sess.span_diagnostic,
                 self.token.span,
                 E0067,
-                "can't reassign to a uninitialized variable"
+                "can't reassign to an uninitialized variable"
             );
             err.span_suggestion_short(
                 self.token.span,
-                "replace with `=` to initialize the variable",
+                "initialize the variable",
                 "=".to_string(),
-                if has_ty {
+                Applicability::MaybeIncorrect,
-                    // for `let x: i8 += 1` it's highly likely that the `+` is a typo
-                    Applicability::MachineApplicable
-                } else {
-                    // for `let x += 1` it's a bit less likely that the `+` is a typo
-                    Applicability::MaybeIncorrect
-                },
             );
             // In case of code like `let x += 1` it's possible the user may have meant to write `x += 1`
             if !has_ty {
                 err.span_suggestion_short(
                     let_span,
-                    "remove to reassign to a previously initialized variable",
+                    "otherwise, reassign to a previously initialized variable",
                     "".to_string(),
                     Applicability::MaybeIncorrect,
                 );

src/test/ui/parser/let-binop-plus.rs

@@ -3,6 +3,6 @@
 fn main() {
     let a: i8 += 1;
     //~^ ERROR expected trait, found builtin type `i8`
-    //~| ERROR can't reassign to a uninitialized variable
+    //~| ERROR can't reassign to an uninitialized variable
     let _ = a;
 }

src/test/ui/parser/let-binop-plus.stderr

@@ -1,8 +1,8 @@
-error[E0067]: can't reassign to a uninitialized variable
+error[E0067]: can't reassign to an uninitialized variable
   --> $DIR/let-binop-plus.rs:4:16
    |
 LL |     let a: i8 += 1;
-   |                ^ help: replace with `=` to initialize the variable
+   |                ^ help: initialize the variable
 
 error[E0404]: expected trait, found builtin type `i8`
   --> $DIR/let-binop-plus.rs:4:12

src/test/ui/parser/let-binop.rs

@@ -1,8 +1,8 @@
 fn main() {
-    let a: i8 *= 1; //~ ERROR can't reassign to a uninitialized variable
+    let a: i8 *= 1; //~ ERROR can't reassign to an uninitialized variable
     let _ = a;
-    let b += 1; //~ ERROR can't reassign to a uninitialized variable
+    let b += 1; //~ ERROR can't reassign to an uninitialized variable
     let _ = b;
-    let c *= 1; //~ ERROR can't reassign to a uninitialized variable
+    let c *= 1; //~ ERROR can't reassign to an uninitialized variable
     let _ = c;
 }

src/test/ui/parser/let-binop.stderr

@@ -1,37 +1,37 @@
-error[E0067]: can't reassign to a uninitialized variable
+error[E0067]: can't reassign to an uninitialized variable
   --> $DIR/let-binop.rs:2:15
    |
 LL |     let a: i8 *= 1;
-   |               ^^ help: replace with `=` to initialize the variable
+   |               ^^ help: initialize the variable
 
-error[E0067]: can't reassign to a uninitialized variable
+error[E0067]: can't reassign to an uninitialized variable
   --> $DIR/let-binop.rs:4:11
    |
 LL |     let b += 1;
    |           ^^
    |
-help: replace with `=` to initialize the variable
+help: initialize the variable
    |
 LL |     let b = 1;
    |           ^
-help: remove to reassign to a previously initialized variable
+help: otherwise, reassign to a previously initialized variable
    |
-LL |      b += 1;
+LL |     b += 1;
    |    --
 
-error[E0067]: can't reassign to a uninitialized variable
+error[E0067]: can't reassign to an uninitialized variable
   --> $DIR/let-binop.rs:6:11
    |
 LL |     let c *= 1;
    |           ^^
    |
-help: replace with `=` to initialize the variable
+help: initialize the variable
    |
 LL |     let c = 1;
    |           ^
-help: remove to reassign to a previously initialized variable
+help: otherwise, reassign to a previously initialized variable
    |
-LL |      c *= 1;
+LL |     c *= 1;
    |    --
 
 error: aborting due to 3 previous errors