Move metadata off the executable heaps (#52912)

* Move metadata off the executable heaps

This change moves metadata structures that manage blocks of heap memory
out of the heaps in preparation for the W^X changes that will make the
heap memory read-execute only and modifying the metadata would require
unnecessary mappings and unmappings of the memory as read-write.

The structures moved in this change are the following:
* LoaderHeapBlock
* FreeBlock
* HeapList

* Remove unnecessary m_pCurBlock from the UnlockedLoaderHeap

1 files changed, 18 insertions, 2 deletions

diff --git a/src/coreclr/inc/loaderheap.h b/src/coreclr/inc/loaderheap.h
index 68d50f6d637..96fec35be0c 100644
--- a/src/coreclr/inc/loaderheap.h
+++ b/src/coreclr/inc/loaderheap.h
@@ -201,8 +201,6 @@ private:
     PTR_BYTE            m_pPtrToEndOfCommittedRegion;
     PTR_BYTE            m_pEndReservedRegion;
 
-    PTR_LoaderHeapBlock m_pCurBlock;
-
     // When we need to ClrVirtualAlloc() MEM_RESERVE a new set of pages, number of bytes to reserve
     DWORD               m_dwReserveBlockSize;
 
@@ -301,6 +299,12 @@ protected:
         return m_pEndReservedRegion - m_pAllocPtr;
     }
 
+    PTR_BYTE UnlockedGetAllocPtr()
+    {
+        LIMITED_METHOD_CONTRACT;
+        return m_pAllocPtr;
+    }
+
 private:
     // Get some more committed pages - either commit some more in the current reserved region, or, if it
     // has run out, reserve another set of pages
@@ -848,6 +852,18 @@ public:
         WRAPPER_NO_CONTRACT;
         return UnlockedGetReservedBytesFree();
     }
+
+    PTR_BYTE GetAllocPtr()
+    {
+        WRAPPER_NO_CONTRACT;
+        return UnlockedGetAllocPtr();
+    }
+
+    void ReservePages(size_t size)
+    {
+        WRAPPER_NO_CONTRACT;
+        UnlockedReservePages(size);
+    }
 };