[mono][llvm] Avoid linking a bblock ending with a NOT_REACHABLE with …

…their successors. (dotnet#97660)

This prevents llvm from failing for methods like Guid.FormatGuidVector128Utf8 ().

src/mono/mono/mini/method-to-ir.c

@@ -7061,11 +7061,14 @@ mono_method_to_ir (MonoCompile *cfg, MonoMethod *method, MonoBasicBlock *start_b
 			emit_set_deopt_il_offset (cfg, GPTRDIFF_TO_INT (ip - cfg->cil_start));
 		} else {
 			if ((tblock = cfg->cil_offset_to_bb [ip - cfg->cil_start]) && (tblock != cfg->cbb)) {
-				link_bblock (cfg, cfg->cbb, tblock);
 				if (sp != stack_start) {
+					link_bblock (cfg, cfg->cbb, tblock);
 					handle_stack_args (cfg, stack_start, GPTRDIFF_TO_INT (sp - stack_start));
 					sp = stack_start;
 					CHECK_UNVERIFIABLE (cfg);
+				} else {
+					if (!(cfg->cbb->last_ins && cfg->cbb->last_ins->opcode == OP_NOT_REACHED))
+						link_bblock (cfg, cfg->cbb, tblock);
 				}
 				cfg->cbb->next_bb = tblock;
 				cfg->cbb = tblock;