rustc: Fail fast when compiling a source file larger than 4 GiB - 1 B

Fixes #132862

compiler/rustc_span/src/lib.rs

@@ -1843,6 +1843,8 @@ impl StableSourceFileId {
 }
 
 impl SourceFile {
+    const MAX_FILE_SIZE: u32 = u32::MAX - 1;
+
     pub fn new(
         name: FileName,
         mut src: String,
@@ -1863,6 +1865,9 @@ impl SourceFile {
         let stable_id = StableSourceFileId::from_filename_in_current_crate(&name);
         let source_len = src.len();
         let source_len = u32::try_from(source_len).map_err(|_| OffsetOverflowError)?;
+        if source_len > Self::MAX_FILE_SIZE {
+            return Err(OffsetOverflowError);
+        }
 
         let (lines, multibyte_chars) = analyze_source_file::analyze_source_file(&src);