Generic dictionary minor performance improvement and simplification for R2R (#5690)

A set of refactoring changes to slighly improve the performance of generic dictionary access on R2R images, and simplifying the codebase:
    1) Removing dependency on CEEInfo::ComputeRuntimeLookupForSharedGenericTokenStatic (and deleting the API).
    2) Stop parsing the generic type/method signatures when generating the R2R dictionary lookup assembly stub.
    3) Avoid re-encoding the generic type/method signatures in a new in-memory blob using a SigBuilder  (signatures used directly from the R2R image)
    4) Moved the parsing/loading of type/method signatures to Dictionary::PopulateEntry()
    5) Dictionary index and slot number are now encoded in the generated assembly stub instead of the signature (stub takes a pointer to a data blob, which contains the signature, the dictionary index and slot, and the module pointer)

1 files changed, 34 insertions, 0 deletions

diff --git a/src/vm/codeman.cpp b/src/vm/codeman.cpp
index 701f5da392..7eea254646 100644
--- a/src/vm/codeman.cpp
+++ b/src/vm/codeman.cpp
@@ -4535,6 +4535,40 @@ PTR_Module ExecutionManager::FindZapModule(TADDR currentData)
 }
 
 /* static */
+PTR_Module ExecutionManager::FindReadyToRunModule(TADDR currentData)
+{
+    CONTRACTL
+    {
+        NOTHROW;
+        GC_NOTRIGGER;
+        SO_TOLERANT;
+        MODE_ANY;
+        STATIC_CONTRACT_HOST_CALLS;
+        SUPPORTS_DAC;
+    }
+    CONTRACTL_END;
+
+#ifdef FEATURE_READYTORUN
+    ReaderLockHolder rlh;
+
+    RangeSection * pRS = GetRangeSection(currentData);
+    if (pRS == NULL)
+        return NULL;
+
+    if (pRS->flags & RangeSection::RANGE_SECTION_CODEHEAP)
+        return NULL;
+
+    if (pRS->flags & RangeSection::RANGE_SECTION_READYTORUN)
+        return dac_cast<PTR_Module>(pRS->pHeapListOrZapModule);;
+
+    return NULL;
+#else
+    return NULL;
+#endif
+}
+
+
+/* static */
 PTR_Module ExecutionManager::FindModuleForGCRefMap(TADDR currentData)
 {
     CONTRACTL