vfmt: prioritize internal error exit code (5) over format-diff exit codes (#26857)

When vfmt encounters both internal errors (e.g. TCC crash processing one
file) and format differences in other files, the old code combined exit
codes: 2 (format diffs with -c) + 5 (internal error) = 7. Exit code 7
is not handled by CI checks that tolerate `exit_code -ne 5`, causing
false failures.

Fix: when has_internal_error is true, exit(5) immediately before
evaluating format-diff errors. The caller already retries with a better
backend when exit code is 5; producing 7 prevents that recovery.

Fixes: #26853 (Format vlang/v-analyzer CI step)

Co-authored-by: Richard Wheeler <18647491+PythonWillRule@users.noreply.github.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: 3 people

cmd/tools/vfmt.v

@@ -145,19 +145,24 @@ fn main() {
 		}
 		errors++
 	}
-	ecode := if has_internal_error { 5 } else { 0 }
+	if has_internal_error {
+		// When some files could not be processed due to internal vfmt errors,
+		// exit with code 5 regardless of format-diff errors in other files.
+		// This prevents exit codes like 7 (2+5) that confuse downstream CI checks.
+		exit(5)
+	}
 	if errors > 0 {
 		if !foptions.is_diff {
 			eprintln('Encountered a total of: ${errors} formatting errors.')
 		}
 		match true {
-			foptions.is_noerror { exit(0 + ecode) }
-			foptions.is_verify { exit(1 + ecode) }
-			foptions.is_c { exit(2 + ecode) }
-			else { exit(1 + ecode) }
+			foptions.is_noerror { exit(0) }
+			foptions.is_verify { exit(1) }
+			foptions.is_c { exit(2) }
+			else { exit(1) }
 		}
 	}
-	exit(ecode)
+	exit(0)
 }
 
 fn (foptions &FormatOptions) verify_file(prefs &pref.Preferences, fpath string) bool {