Runtime support for static virtual interface methods (#52173)

This change implements initial CoreCLR runtime support for static virtual interface methods and adds over 1700 test cases covering various aspects of this new runtime feature.

1) In the JIT, we are relaxing the assumption that ".constrained" must be always followed by a "callvirt" by allowing two more IL instructions to be constrained, "call" and "ldftn".

2) In the JIT interface, we're adding bits of code to CEEInfo::getCallInfo to properly handle the new static virtual methods. We're extending constrained method resolution to cater for the static virtual method case in a new method "ResolveStaticVirtualMethod".

3) In our work on the implementation we found a pre-existing JIT interface issue - the interplay between getCallInfo and embedGenericHandle doesn't work well in case of constrained calls as the existing API surface doesn't provide any means for communicating compile-time resolution of the constraint from getCallInfo to embedGenericHandle. In this change we're working around this by deferring to runtime resolution of the constraint in the presence of shared generics.

4) In the method table builder, we're newly tracking a flag saying whether we're implementing an interface declaring static virtual methods (fHasVirtualStaticMethods) that is used to speed up the runtime checks by skipping irrelevant interfaces.

5) For Crossgen / Crossgen2, this change only adds minimalistic support in the form of bailing out in getCallInfo whenever we hit a call to a static virtual method, cancelling AOT compilation of the caller and deferring it to runtime JIT.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/coreclr/tools/aot/ILCompiler.ReadyToRun/JitInterface/CorInfoImpl.ReadyToRun.cs b/src/coreclr/tools/aot/ILCompiler.ReadyToRun/JitInterface/CorInfoImpl.ReadyToRun.cs
index 2c4333fc974..0119522f0af 100644
--- a/src/coreclr/tools/aot/ILCompiler.ReadyToRun/JitInterface/CorInfoImpl.ReadyToRun.cs
+++ b/src/coreclr/tools/aot/ILCompiler.ReadyToRun/JitInterface/CorInfoImpl.ReadyToRun.cs
@@ -1818,6 +1818,13 @@ namespace Internal.JitInterface
 
         private void getCallInfo(ref CORINFO_RESOLVED_TOKEN pResolvedToken, CORINFO_RESOLVED_TOKEN* pConstrainedResolvedToken, CORINFO_METHOD_STRUCT_* callerHandle, CORINFO_CALLINFO_FLAGS flags, CORINFO_CALL_INFO* pResult)
         {
+            if ((flags & CORINFO_CALLINFO_FLAGS.CORINFO_CALLINFO_CALLVIRT) == 0 && pConstrainedResolvedToken != null)
+            {
+                // Defer constrained call / ldftn instructions used for static virtual methods
+                // to runtime resolution.
+                throw new RequiresRuntimeJitException("SVM");
+            }
+
             MethodDesc methodToCall;
             MethodDesc targetMethod;
             TypeDesc constrainedType;