Work around a Visual C++ silent bad code generation bug (#7890)

Fixes #7837

The full description of the problem is in that issue.

Author: BruceForstall

src/vm/dllimportcallback.cpp

@@ -1320,7 +1320,9 @@ MethodDesc* UMThunkMarshInfo::GetILStubMethodDesc(MethodDesc* pInvokeMD, PInvoke
     dwStubFlags |= NDIRECTSTUB_FL_REVERSE_INTEROP;  // could be either delegate interop or not--that info is passed in from the caller
 
 #if defined(DEBUGGING_SUPPORTED)
-    if (GetDebuggerCompileFlags(pSigInfo->GetModule(), CORJIT_FLAGS()).IsSet(CORJIT_FLAGS::CORJIT_FLAG_DEBUG_CODE))
+    // Combining the next two lines, and eliminating jitDebuggerFlags, leads to bad codegen in x86 Release builds using Visual C++ 19.00.24215.1.
+    CORJIT_FLAGS jitDebuggerFlags = GetDebuggerCompileFlags(pSigInfo->GetModule(), CORJIT_FLAGS());
+    if (jitDebuggerFlags.IsSet(CORJIT_FLAGS::CORJIT_FLAG_DEBUG_CODE))
     {
         dwStubFlags |= NDIRECTSTUB_FL_GENERATEDEBUGGABLEIL;
     }
@@ -1394,7 +1396,9 @@ VOID UMThunkMarshInfo::RunTimeInit()
         DWORD dwStubFlags = NDIRECTSTUB_FL_NGENEDSTUB | NDIRECTSTUB_FL_REVERSE_INTEROP | NDIRECTSTUB_FL_DELEGATE;
 
 #if defined(DEBUGGING_SUPPORTED)
-        if (GetDebuggerCompileFlags(GetModule(), CORJIT_FLAGS()).IsSet(CORJIT_FLAGS::CORJIT_FLAG_DEBUG_CODE))
+        // Combining the next two lines, and eliminating jitDebuggerFlags, leads to bad codegen in x86 Release builds using Visual C++ 19.00.24215.1.
+        CORJIT_FLAGS jitDebuggerFlags = GetDebuggerCompileFlags(GetModule(), CORJIT_FLAGS());
+        if (jitDebuggerFlags.IsSet(CORJIT_FLAGS::CORJIT_FLAG_DEBUG_CODE))
         {
             dwStubFlags |= NDIRECTSTUB_FL_GENERATEDEBUGGABLEIL;
         }

src/vm/jitinterface.cpp

@@ -7394,11 +7394,15 @@ CorInfoInline CEEInfo::canInline (CORINFO_METHOD_HANDLE hCaller,
 
     // If the callee wants debuggable code, don't allow it to be inlined
 
-    if (GetDebuggerCompileFlags(pCallee->GetModule(), CORJIT_FLAGS()).IsSet(CORJIT_FLAGS::CORJIT_FLAG_DEBUG_CODE))
     {
-        result = INLINE_NEVER;
-        szFailReason = "Inlinee is debuggable";
-        goto exit;
+        // Combining the next two lines, and eliminating jitDebuggerFlags, leads to bad codegen in x86 Release builds using Visual C++ 19.00.24215.1.
+        CORJIT_FLAGS jitDebuggerFlags = GetDebuggerCompileFlags(pCallee->GetModule(), CORJIT_FLAGS());
+        if (jitDebuggerFlags.IsSet(CORJIT_FLAGS::CORJIT_FLAG_DEBUG_CODE))
+        {
+            result = INLINE_NEVER;
+            szFailReason = "Inlinee is debuggable";
+            goto exit;
+        }
     }
 #endif