Overhaul ToString in the type system (#5065)

This is fixing several problems with how we did `ToString`:
* The existing scheme required every `TypeDesc`/`MethodDesc`/`FieldDesc` descendant to override `ToString`. Of course we were not consistent with this and as a result, most of our synthetic type system entities had non-existent representation in the debugger. Overriding is a lot of boilerplate.
* We were not flexible with the stringified names. E.g. instantiated types became too long because we were module- and namespace- qualifying everything.
* (Minor) The runtime type loader was shipping with ToString support in retail configuration that was largely unused.

With the new scheme, besides fixing the problems above, I'm adding a bunch of conveniences:
* `MethodDesc` now also have signatures in their `ToString`.
* Well-known primitive types have short aliases
* System.Private prefix is shortened to S.P.

I tested that the `TYPE_LOADER_TRACE` still works after this. The runtime type loader overrides the `ToString` in all the places that matter.

2 files changed, 12 insertions, 5 deletions

diff --git a/src/ILCompiler.TypeSystem/src/ILCompiler.TypeSystem.csproj b/src/ILCompiler.TypeSystem/src/ILCompiler.TypeSystem.csproj
index 227d6b4be..af067a0ad 100644
--- a/src/ILCompiler.TypeSystem/src/ILCompiler.TypeSystem.csproj
+++ b/src/ILCompiler.TypeSystem/src/ILCompiler.TypeSystem.csproj
@@ -121,6 +121,9 @@
     <Compile Include="..\..\Common\src\TypeSystem\Common\Utilities\CustomAttributeTypeNameParser.cs">
       <Link>Utilities\CustomAttributeTypeNameParser.cs</Link>
     </Compile>
+    <Compile Include="..\..\Common\src\TypeSystem\Common\Utilities\DebugNameFormatter.cs">
+      <Link>Utilities\DebugNameFormatter.cs</Link>
+    </Compile>
     <Compile Include="..\..\Common\src\TypeSystem\Common\Utilities\GCPointerMap.Algorithm.cs">
       <Link>Utilities\GCPointerMap.Algorithm.cs</Link>
     </Compile>
@@ -154,6 +157,9 @@
     <Compile Include="..\..\Common\src\TypeSystem\Common\FieldDesc.cs">
       <Link>TypeSystem\Common\FieldDesc.cs</Link>
     </Compile>
+    <Compile Include="..\..\Common\src\TypeSystem\Common\FieldDesc.ToString.cs">
+      <Link>TypeSystem\Common\FieldDesc.ToString.cs</Link>
+    </Compile>
     <Compile Include="..\..\Common\src\TypeSystem\Common\FieldDesc.FieldLayout.cs">
       <Link>TypeSystem\Common\FieldDesc.FieldLayout.cs</Link>
     </Compile>
@@ -250,12 +256,18 @@
     <Compile Include="..\..\Common\src\TypeSystem\Common\MethodDesc.cs">
       <Link>TypeSystem\Common\MethodDesc.cs</Link>
     </Compile>
+    <Compile Include="..\..\Common\src\TypeSystem\Common\MethodDesc.ToString.cs">
+      <Link>TypeSystem\Common\MethodDesc.ToString.cs</Link>
+    </Compile>
     <Compile Include="..\..\Common\src\TypeSystem\Common\MetadataVirtualMethodAlgorithm.cs">
       <Link>TypeSystem\Common\StandardVirtualMethodAlgorithm.cs</Link>
     </Compile>
     <Compile Include="..\..\Common\src\TypeSystem\Common\TypeDesc.cs">
       <Link>TypeSystem\Common\TypeDesc.cs</Link>
     </Compile>
+    <Compile Include="..\..\Common\src\TypeSystem\Common\TypeDesc.ToString.cs">
+      <Link>TypeSystem\Common\TypeDesc.ToString.cs</Link>
+    </Compile>
     <Compile Include="..\..\Common\src\TypeSystem\Common\TypeDesc.Interfaces.cs">
       <Link>TypeSystem\Common\TypeDesc.Interfaces.cs</Link>
     </Compile>
diff --git a/src/ILCompiler.TypeSystem/tests/SyntheticVirtualOverrideTests.cs b/src/ILCompiler.TypeSystem/tests/SyntheticVirtualOverrideTests.cs
index 66c387bf3..0058db8a6 100644
--- a/src/ILCompiler.TypeSystem/tests/SyntheticVirtualOverrideTests.cs
+++ b/src/ILCompiler.TypeSystem/tests/SyntheticVirtualOverrideTests.cs
@@ -226,11 +226,6 @@ namespace TypeSystemTests
             {
                 return false;
             }
-
-            public override string ToString()
-            {
-                return "[::Synthetic]" + _owningType.ToString() + "." + _name;
-            }
         }
     }
 }