Update DBG_MAX_EXECUTABLE_ALLOC_SIZE and EXPECTED_CHUNKSIZE (#117843)

* Update DBG_MAX_EXECUTABLE_ALLOC_SIZE and EXPECTED_CHUNKSIZE to account recent SharedPatchBypassBuffer changes

* Comment-only update

Co-authored-by: Copilot <[email protected]>

* Improve EXPECTED_CHUNKSIZE comment

---------

Co-authored-by: Copilot <[email protected]>

Author: tommcdon

src/coreclr/debug/ee/debugger.h

@@ -1116,8 +1116,8 @@ class DebuggerMethodInfo
 //     different part of the address space (not on the heap).
 // ------------------------------------------------------------------------ */
 
-constexpr uint64_t DBG_MAX_EXECUTABLE_ALLOC_SIZE=112;
-constexpr uint64_t EXPECTED_CHUNKSIZE=128;
+constexpr uint64_t DBG_MAX_EXECUTABLE_ALLOC_SIZE=120; // sizeof (SharedPatchBypassBuffer)
+constexpr uint64_t EXPECTED_CHUNKSIZE=256; // This must be a power of 2.  It represents the size of DebuggerHeapExecutableMemoryChunk, can be the sizeof (DataChunk) or sizeof (BookkeepingChunk). Changes to DBG_MAX_EXECUTABLE_ALLOC_SIZE can affect this number.  Currently we require 136 bytes, and so the closest power of 2 is 256.
 constexpr uint64_t DEBUGGERHEAP_PAGESIZE=4096;
 constexpr uint64_t CHUNKS_PER_DEBUGGERHEAP=(DEBUGGERHEAP_PAGESIZE / EXPECTED_CHUNKSIZE);
 constexpr uint64_t MAX_CHUNK_MASK=((1ull << CHUNKS_PER_DEBUGGERHEAP) - 1);