8294467: Fix sequence-point warnings in Hotspot

Reviewed-by: dholmes, thartmann, roland

Author: shipilev

make/hotspot/lib/CompileJvm.gmk

@@ -161,7 +161,6 @@ $(eval $(call SetupJdkLibrary, BUILD_LIBJVM, \
     DISABLED_WARNINGS_gcc_cgroupV2Subsystem_linux.cpp := address, \
     DISABLED_WARNINGS_gcc_interp_masm_x86.cpp := uninitialized, \
     DISABLED_WARNINGS_gcc_javaClasses.cpp := misleading-indentation, \
-    DISABLED_WARNINGS_gcc_loopnode.cpp := sequence-point, \
     DISABLED_WARNINGS_gcc_postaloc.cpp := address, \
     DISABLED_WARNINGS_gcc_sharedRuntimeTrig.cpp := misleading-indentation, \
     DISABLED_WARNINGS_gcc_shenandoahBarrierSet.cpp := misleading-indentation, \

src/hotspot/share/opto/loopnode.cpp

@@ -1394,7 +1394,7 @@ void PhaseIdealLoop::transform_long_range_checks(int stride_con, const Node_List
     set_ctrl(K, this->C->root());
     Node* scaled_iv = new MulINode(inner_phi, K);
     register_new_node(scaled_iv, c);
-    Node* scaled_iv_plus_offset = scaled_iv_plus_offset = new AddINode(scaled_iv, L_2);
+    Node* scaled_iv_plus_offset = new AddINode(scaled_iv, L_2);
     register_new_node(scaled_iv_plus_offset, c);
 
     Node* new_rc_cmp = new CmpUNode(scaled_iv_plus_offset, R_2);