unnecessary_operation: add space between stmts in suggestion (rust-lang#15432)

makes the suggestion a bit more legible

changelog: [`unnecessary_operation`]: add space between stmts in
suggestion

Author: y21

clippy_lints/src/no_effect.rs

@@ -305,11 +305,12 @@ fn check_unnecessary_operation(cx: &LateContext<'_>, stmt: &Stmt<'_>) {
             for e in reduced {
                 if let Some(snip) = e.span.get_source_text(cx) {
                     snippet.push_str(&snip);
-                    snippet.push(';');
+                    snippet.push_str("; ");
                 } else {
                     return;
                 }
             }
+            snippet.pop(); // remove the last space
             span_lint_hir_and_then(
                 cx,
                 UNNECESSARY_OPERATION,

tests/ui/unnecessary_operation.fixed

@@ -78,25 +78,25 @@ fn main() {
     //~^ unnecessary_operation
     get_number();
     //~^ unnecessary_operation
-    5;get_number();
+    5; get_number();
     //~^ unnecessary_operation
     get_number();
     //~^ unnecessary_operation
     get_number();
     //~^ unnecessary_operation
-    5;6;get_number();
+    5; 6; get_number();
     //~^ unnecessary_operation
     get_number();
     //~^ unnecessary_operation
     get_number();
     //~^ unnecessary_operation
-    5;get_number();
+    5; get_number();
     //~^ unnecessary_operation
-    42;get_number();
+    42; get_number();
     //~^ unnecessary_operation
     assert!([42, 55].len() > get_usize());
     //~^ unnecessary_operation
-    42;get_number();
+    42; get_number();
     //~^ unnecessary_operation
     get_number();
     //~^ unnecessary_operation

tests/ui/unnecessary_operation.stderr

@@ -35,7 +35,7 @@ error: unnecessary operation
   --> tests/ui/unnecessary_operation.rs:81:5
    |
 LL |     5 + get_number();
-   |     ^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5;get_number();`
+   |     ^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5; get_number();`
 
 error: unnecessary operation
   --> tests/ui/unnecessary_operation.rs:83:5
@@ -53,7 +53,7 @@ error: unnecessary operation
   --> tests/ui/unnecessary_operation.rs:87:5
    |
 LL |     (5, 6, get_number());
-   |     ^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5;6;get_number();`
+   |     ^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5; 6; get_number();`
 
 error: unnecessary operation
   --> tests/ui/unnecessary_operation.rs:89:5
@@ -71,13 +71,13 @@ error: unnecessary operation
   --> tests/ui/unnecessary_operation.rs:93:5
    |
 LL |     5..get_number();
-   |     ^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5;get_number();`
+   |     ^^^^^^^^^^^^^^^^ help: statement can be reduced to: `5; get_number();`
 
 error: unnecessary operation
   --> tests/ui/unnecessary_operation.rs:95:5
    |
 LL |     [42, get_number()];
-   |     ^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `42;get_number();`
+   |     ^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `42; get_number();`
 
 error: unnecessary operation
   --> tests/ui/unnecessary_operation.rs:97:5
@@ -89,7 +89,7 @@ error: unnecessary operation
   --> tests/ui/unnecessary_operation.rs:99:5
    |
 LL |     (42, get_number()).1;
-   |     ^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `42;get_number();`
+   |     ^^^^^^^^^^^^^^^^^^^^^ help: statement can be reduced to: `42; get_number();`
 
 error: unnecessary operation
   --> tests/ui/unnecessary_operation.rs:101:5