Rollup merge of #128864 - jieyouxu:funnicode, r=Urgau

Use `SourceMap::end_point` instead of `- BytePos(1)` in arg removal suggestion

Previously, we tried to remove extra arg commas when providing extra arg removal suggestions. One of
the edge cases is having to account for an arg that has a closing delimiter `)` following it.
However, the previous suggestion code assumed that the delimiter is in fact exactly the 1-byte `)`
character. This assumption was proven incorrect, because we recover from Unicode-confusable
delimiters in the parser, which means that the ending delimiter could be a multi-byte codepoint
that looks *like* a `)`. Subtracing 1 byte could land us in the middle of a codepoint, triggering a
codepoint boundary assertion.

This is fixed by using `SourceMap::end_point` which properly accounts for codepoint boundaries.

Fixes #128717.

cc ````@fmease```` and #128790

1 files changed, 6 insertions, 3 deletions

diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index cef003e0a43..89e7227eda2 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -22,7 +22,7 @@ use rustc_middle::ty::{self, IsSuggestable, Ty, TyCtxt};
 use rustc_middle::{bug, span_bug};
 use rustc_session::Session;
 use rustc_span::symbol::{kw, Ident};
-use rustc_span::{sym, BytePos, Span, DUMMY_SP};
+use rustc_span::{sym, Span, DUMMY_SP};
 use rustc_trait_selection::error_reporting::infer::{FailureCode, ObligationCauseExt};
 use rustc_trait_selection::infer::InferCtxtExt;
 use rustc_trait_selection::traits::{self, ObligationCauseCode, SelectionContext};
@@ -1140,8 +1140,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 .get(arg_idx + 1)
                                 .map(|&(_, sp)| sp)
                                 .unwrap_or_else(|| {
-                                    // Subtract one to move before `)`
-                                    call_expr.span.with_lo(call_expr.span.hi() - BytePos(1))
+                                    // Try to move before `)`. Note that `)` here is not necessarily
+                                    // the latin right paren, it could be a Unicode-confusable that
+                                    // looks like a `)`, so we must not use `- BytePos(1)`
+                                    // manipulations here.
+                                    self.tcx().sess.source_map().end_point(call_expr.span)
                                 });
 
                             // Include next comma