JIT: recover types from helper calls and more (#20447)

The jit needs to recover class handles in order to devirtualize and
do other type-based optimizations. This change allows the jit to find
the type for more trees: in particular, helper calls, intrinsics, and
expanded static field accesses.

Also, annotate a few methods to control jit optimization

We don't want to optimize special methods that are used to inform crossgen
about desirable generic instantiations. `CommonlyUsedGenericInstantiations`
was already annotated but `CommonlyUsedWinRTRedirectedInterfaceStubs` wasn't.

And because `RuntimeType` is sealed calls through types are now often
devirtualized. Name lookups on types are frequent, especially on error paths.
The method `GetCachedName` looks like an attractive inline but simply expands
into a larger sequence of two other calls. So block it from being inlined.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/System.Private.CoreLib/src/System/RtType.cs b/src/System.Private.CoreLib/src/System/RtType.cs
index 0e5cf8104e..63cf950d9d 100644
--- a/src/System.Private.CoreLib/src/System/RtType.cs
+++ b/src/System.Private.CoreLib/src/System/RtType.cs
@@ -4532,6 +4532,10 @@ namespace System
             }
         }
 
+        // This method looks like an attractive inline but expands to two calls,
+        // neither of which can be inlined or optimized further. So block it
+        // from inlining.
+        [MethodImpl(MethodImplOptions.NoInlining)]
         private string GetCachedName(TypeNameKind kind)
         {
             return Cache.GetName(kind);