add isVolGlobal to DivDispatch

do not key release on pendingNotes if so
issue #1325

src/engine/platform/abstract.cpp

@@ -86,6 +86,10 @@ bool DivDispatch::keyOffAffectsPorta(int ch) {
   return false;
 }
 
+bool DivDispatch::isVolGlobal() {
+  return false;
+}
+
 int DivDispatch::getPortaFloor(int ch) {
   return 0x00;
 }

src/engine/platform/c64.cpp

@@ -566,6 +566,10 @@ bool DivPlatformC64::getWantPreNote() {
   return true;
 }
 
+bool DivPlatformC64::isVolGlobal() {
+  return true;
+}
+
 float DivPlatformC64::getPostAmp() {
   return (sidCore==1)?3.0f:1.0f;
 }

src/engine/platform/c64.h

@@ -105,6 +105,7 @@ class DivPlatformC64: public DivDispatch {
     void notifyInsChange(int ins);
     bool getDCOffRequired();
     bool getWantPreNote();
+    bool isVolGlobal();
     float getPostAmp();
     DivMacroInt* getChanMacroInt(int ch);
     void notifyInsDeletion(void* ins);

src/engine/platform/ted.cpp

@@ -257,6 +257,10 @@ void DivPlatformTED::forceIns() {
   updateCtrl=true;
 }
 
+bool DivPlatformTED::isVolGlobal() {
+  return true;
+}
+
 void* DivPlatformTED::getChanState(int ch) {
   return &chan[ch];
 }

src/engine/platform/ted.h

@@ -54,6 +54,7 @@ class DivPlatformTED: public DivDispatch {
   public:
     void acquire(short** buf, size_t len);
     int dispatch(DivCommand c);
+    bool isVolGlobal();
     void* getChanState(int chan);
     DivMacroInt* getChanMacroInt(int ch);
     DivDispatchOscBuffer* getOscBuffer(int chan);

src/engine/platform/vic20.cpp

@@ -278,6 +278,10 @@ void DivPlatformVIC20::forceIns() {
   }
 }
 
+bool DivPlatformVIC20::isVolGlobal() {
+  return true;
+}
+
 void* DivPlatformVIC20::getChanState(int ch) {
   return &chan[ch];
 }

src/engine/platform/vic20.h

@@ -46,6 +46,7 @@ class DivPlatformVIC20: public DivDispatch {
   public:
     void acquire(short** buf, size_t len);
     int dispatch(DivCommand c);
+    bool isVolGlobal();
     void* getChanState(int chan);
     DivMacroInt* getChanMacroInt(int ch);
     DivDispatchOscBuffer* getOscBuffer(int chan);