Do not confuse fgDispBasicBlocks in fgMorphBlocks

The logic in "fgDispBasicBlocks" has a check for promoted implicit by-refs
that only allows them during global morph via an 'assert(fgGlobalMorph)'.
However, "fgMorphBlocks" was calling "fgDispBasicBlocks" after having set "fgGlobalMorph" to "false",
leading it to falsely believe it was not actually being called during global morph
and asserting with a message like "assertion failed 'fgGlobalMorph' - during 'Morph - Global'".
Fix this by setting "fgGlobalMorph" to "false" at the very end of "fgMorphBlocks".

src/coreclr/jit/morph.cpp

@@ -17226,10 +17226,6 @@ void Compiler::fgMorphBlocks()
         block = block->bbNext;
     } while (block != nullptr);
 
-    // We are done with the global morphing phase
-    fgGlobalMorph = false;
-    compCurBB     = nullptr;
-
     // Under OSR, we no longer need to specially protect the original method entry
     //
     if (opts.IsOSR() && (fgEntryBB != nullptr) && (fgEntryBB->bbFlags & BBF_IMPORTED))
@@ -17247,6 +17243,10 @@ void Compiler::fgMorphBlocks()
         fgDispBasicBlocks(true);
     }
 #endif
+
+    // We are done with the global morphing phase
+    fgGlobalMorph = false;
+    compCurBB     = nullptr;
 }
 
 //------------------------------------------------------------------------