fix(error): normalize whitespace during msg_to_buffer

compiler/rustc_errors/src/emitter.rs

@@ -1336,6 +1336,7 @@ impl EmitterWriter {
         //                see?
         for (text, style) in msg.iter() {
             let text = self.translate_message(text, args).map_err(Report::new).unwrap();
+            let text = &normalize_whitespace(&text);
             let lines = text.split('\n').collect::<Vec<_>>();
             if lines.len() > 1 {
                 for (i, line) in lines.iter().enumerate() {

tests/ui/extenv/issue-110547.rs

@@ -0,0 +1,7 @@
+// compile-flags: -C debug-assertions
+
+fn main() {
+    env!{"\t"}; //~ ERROR not defined at compile time
+    env!("\t"); //~ ERROR not defined at compile time
+    env!("\u{2069}"); //~ ERROR not defined at compile time
+}

tests/ui/extenv/issue-110547.stderr

@@ -0,0 +1,29 @@
+error: environment variable `    ` not defined at compile time
+  --> $DIR/issue-110547.rs:4:5
+   |
+LL |     env!{"\t"};
+   |     ^^^^^^^^^^
+   |
+   = help: use `std::env::var("    ")` to read the variable at run time
+   = note: this error originates in the macro `env` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: environment variable `    ` not defined at compile time
+  --> $DIR/issue-110547.rs:5:5
+   |
+LL |     env!("\t");
+   |     ^^^^^^^^^^
+   |
+   = help: use `std::env::var("    ")` to read the variable at run time
+   = note: this error originates in the macro `env` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: environment variable `` not defined at compile time
+  --> $DIR/issue-110547.rs:6:5
+   |
+LL |     env!("\u{2069}");
+   |     ^^^^^^^^^^^^^^^^
+   |
+   = help: use `std::env::var("")` to read the variable at run time
+   = note: this error originates in the macro `env` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 3 previous errors
+