[Records] CFE crashes with "Internal problem" on typedefs for record types

[alexmarkov]

Part of #49713.

typedef Foo = (int, int);
void main() {
  Foo x = (1, 2);
}

Crash when compiling:
foo.dart:1:9: Internal problem: Unhandled (int, int) in build.
typedef Foo = (int, int);
        ^

#0      internalProblem (package:front_end/src/fasta/problems.dart:52:5)
#1      unhandled (package:front_end/src/fasta/problems.dart:71:10)
#2      SourceTypeAliasBuilder.build (package:front_end/src/fasta/source/source_type_alias_builder.dart:99:7)
#3      SourceLibraryBuilder._buildOutlineNodes (package:front_end/src/fasta/source/source_library_builder.dart:3140:37)
#4      SourceLibraryBuilder.buildOutlineNodes (package:front_end/src/fasta/source/source_library_builder.dart:1094:7)
#5      SourceLoader.buildOutlineNodes (package:front_end/src/fasta/source/source_loader.dart:2056:32)
#6      KernelTarget.buildOutlines.<anonymous closure> (package:front_end/src/fasta/kernel/kernel_target.dart:476:14)
<asynchronous suspension>
#7      withCrashReporting (package:front_end/src/fasta/crash.dart:136:12)
<asynchronous suspension>
#8      _buildInternal (package:front_end/src/kernel_generator_impl.dart:143:7)
<asynchronous suspension>
#9      withCrashReporting (package:front_end/src/fasta/crash.dart:136:12)
<asynchronous suspension>
#10     generateKernel.<anonymous closure> (package:front_end/src/kernel_generator_impl.dart:48:12)
<asynchronous suspension>
#11     generateKernel (package:front_end/src/kernel_generator_impl.dart:47:10)
<asynchronous suspension>
#12     kernelForModule (package:front_end/src/api_prototype/kernel_generator.dart:100:11)
<asynchronous suspension>
#13     SingleShotCompilerWrapper.compileInternal (file:///.../sdk/pkg/vm/bin/kernel_service.dart:412:11)
<asynchronous suspension>
#14     Compiler.compile.<anonymous closure> (file:///.../sdk/pkg/vm/bin/kernel_service.dart:221:45)
<asynchronous suspension>
#15     _processLoadRequest (file:///.../sdk/pkg/vm/bin/kernel_service.dart:914:37)
<asynchronous suspension>

@johnniwinther