fix build in old compiler

src/engine/platform/sound/ymfm/ymfm_opn.h

@@ -763,7 +763,7 @@ public:
 
 protected:
 	// simulate the DAC discontinuity
-	constexpr int32_t dac_discontinuity(int32_t value) const { return (value < 0) ? (value - 2) : (value + 3); }
+	int32_t dac_discontinuity(int32_t value) const { return (value < 0) ? (value - 2) : (value + 3); }
 
 	// internal state
 	uint16_t m_address;              // address register

src/gui/gui.cpp

@@ -3406,7 +3406,9 @@ String getHomeDir() {
     ret=tempDir;
     ret+='\\';
 #else
-    getcwd(tempDir,4095);
+    char* unused=getcwd(tempDir,4095);
+    char* unused1=unused; // dang it compiler
+    unused=unused1;
     ret=tempDir;
     ret+='/';
 #endif