Remove verbose formatting of instructions on crash messages. (#4495)

Undoes a chunk of #4125 because nobody's really in favor of keeping the
formatting, and it's occasionally caused a crash in Formatter to
dominate output (and even when working, it can be verbose; the source
location in (5) is often more helpful).

Basically goes back to:

```
4.	Check::Context
          NodeStack:
            0. LetIntroducer: no value
            1. BindingPattern: inst+15
            2. LetInitializer: no value
            3. StructLiteralStart: no value
          inst_block_stack_:
            0.	block<invalid>	{inst+0, inst+1, inst+6, inst+7, inst+8, inst+9, inst+10, inst+11, inst+12}
            1.	global_init	{}
          pattern_block_stack_:
            0.	block<invalid>	{}
          param_and_arg_refs_stack:
            0.	block<invalid>	{}
          args_type_info_stack_:
            0.	block<invalid>	{}
5.	alias_of_alias.carbon:15:12: checking StructLiteral
          let d: c = {};
                     ^~
```

Fixes #4145

toolchain/check/node_stack.cpp

@@ -8,19 +8,15 @@
 
 namespace Carbon::Check {
 
-auto NodeStack::PrintForStackDump(SemIR::Formatter& formatter, int indent,
-                                  llvm::raw_ostream& output) const -> void {
+auto NodeStack::PrintForStackDump(int indent, llvm::raw_ostream& output) const
+    -> void {
   auto print_id = [&]<Id::Kind Kind>(Id id) {
     if constexpr (Kind == Id::Kind::None) {
-      output << "no value\n";
+      output << "no value";
     } else if constexpr (Kind == Id::Kind::Invalid) {
       CARBON_FATAL("Should not be in node stack");
-    } else if constexpr (Kind == Id::KindFor<SemIR::InstId>()) {
-      output << "\n";
-      formatter.PrintInst(id.As<Id::KindFor<SemIR::InstId>()>(), indent + 4,
-                          output);
     } else {
-      output << id.As<Kind>() << "\n";
+      output << id.As<Kind>();
     }
   };
 
@@ -37,6 +33,7 @@ auto NodeStack::PrintForStackDump(SemIR::Formatter& formatter, int indent,
     break;
 #include "toolchain/parse/node_kind.def"
     }
+    output << "\n";
   }
 }