Implement GcInfo v2 for X86

This commit includes the following changes:
1) Thread GcInfo version through X86 specific APIs
2) Add ReturnKind and ReversePinvokeOffset fields to InfoHdr structure
   GcInfo v1 and v2 use the same InfoHdr structures, because:
   InfoHdrSmall: ReturnKind is encoded within previously unused bits.
   InfoHdr: revPInvokeOffset will never be written to the image,
            since ReversePinvokeOffset==INVALID_REV_PINVOKE_OFFSET for V1.
3) Update the Pre-computed header table to include bits for the above
   [The default setting of ReturnKind=RT_Scalar is used for all entries in the table.
    Optimizing this table based in most frequent usage scenarios is to be done separately]
4) Change the GC encoder/decoder to handle the above two fields
5) Use the ReturnKind in the GCInfo from thread-suspension code.

GcInfo version is changed for CoreCLR X86 only, not for Desktop JIT
Fixes #4379

1 files changed, 3 insertions, 2 deletions

diff --git a/src/vm/proftoeeinterfaceimpl.cpp b/src/vm/proftoeeinterfaceimpl.cpp
index fee883f0ef..20dceed1e4 100644
--- a/src/vm/proftoeeinterfaceimpl.cpp
+++ b/src/vm/proftoeeinterfaceimpl.cpp
@@ -7081,12 +7081,13 @@ Loop:
 
             // GC info will assist us in determining whether this is a non-EBP frame and
             // info about pushed arguments.
-            PTR_VOID gcInfo = codeInfo.GetGCInfo();
+            GCInfoToken gcInfoToken = codeInfo.GetGCInfoToken();
+            PTR_VOID gcInfo = gcInfoToken.Info;
             InfoHdr header;
             unsigned uiMethodSizeDummy;
             PTR_CBYTE table = PTR_CBYTE(gcInfo);
             table += decodeUnsigned(table, &uiMethodSizeDummy);
-            table = decodeHeader(table, &header);
+            table = decodeHeader(table, gcInfoToken.Version, &header);
 
             // Ok, GCInfo, can we do a simple EBP walk or what?