Properly rename EnterNode scope after code coverage insertion (#52720)

Fixes #52672 and changes the emission path to move the error to the
point of corruption instead of the point of first use.

Author: Keno

base/compiler/optimize.jl

@@ -1379,7 +1379,11 @@ function renumber_ir_elements!(body::Vector{Any}, ssachangemap::Vector{Int}, lab
                     @assert !isdefined(el, :scope)
                     body[i] = nothing
                 else
-                    body[i] = EnterNode(el, tgt + labelchangemap[tgt])
+                    if isdefined(el, :scope) && isa(el.scope, SSAValue)
+                        body[i] = EnterNode(tgt + labelchangemap[tgt], SSAValue(el.scope.id + ssachangemap[el.scope.id]))
+                    else
+                        body[i] = EnterNode(el, tgt + labelchangemap[tgt])
+                    end
                 end
             end
         elseif isa(el, Expr)

src/codegen.cpp

@@ -8765,6 +8765,14 @@ static jl_llvm_functions_t
             jl_aliasinfo_t scope_ai = jl_aliasinfo_t::fromTBAA(ctx, ctx.tbaa().tbaa_gcframe);
             if (jl_enternode_scope(stmt)) {
                 jl_cgval_t new_scope = emit_expr(ctx, jl_enternode_scope(stmt));
+                if (new_scope.typ == jl_bottom_type) {
+                    // Probably dead code, but let's be loud about it in case it isn't, so we fail
+                    // at the point of the miscompile, rather than later when something attempts to
+                    // read the scope.
+                    emit_error(ctx, "(INTERNAL ERROR): Attempted to execute EnterNode with bad scope");
+                    find_next_stmt(-1);
+                    continue;
+                }
                 Value *new_scope_boxed = boxed(ctx, new_scope);
                 scope_ptr = get_scope_field(ctx);
                 old_scope = scope_ai.decorateInst(