Fix GCC common symbols

- For now lets just link those against GLN64
- They never run at the same time, are same type and it lowers maintenance efforts

GLideN64/src/N64.cpp

@@ -1,8 +1,18 @@
 #include "N64.h"
 
 u8 *HEADER;
-u8 *DMEM;
-u8 *IMEM;
+
+/* 
+    DMEM and IMEM conflict with CXD4 with GCC 10.x
+    It's defined as pu8 so it's the same type as used in GLN64, just typedef'd.
+    Since we never run both at the same time, let's just link CXD4's to this
+    Also we always assume that we will build with GLideN64 at all times
+*/
+extern "C" {
+    u8 *DMEM;
+    u8 *IMEM;
+}
+
 u64 TMEM[512];
 u8 *RDRAM;
 

GLideN64/src/N64.h

@@ -38,8 +38,13 @@ struct N64Regs
 
 extern N64Regs REG;
 extern u8 *HEADER;
-extern u8 *DMEM;
-extern u8 *IMEM;
+
+extern "C" {
+	// See comment in N64.cpp
+	extern u8 *DMEM;
+	extern u8 *IMEM;
+}
+
 extern u8 *RDRAM;
 extern u64 TMEM[512];
 extern u32 RDRAMSize;

mupen64plus-rsp-cxd4/su.c

@@ -27,8 +27,10 @@ u32 SR[32];
 typedef VECTOR_OPERATION(*p_vector_func)(v16, v16);
 
 pu8 DRAM;
-pu8 DMEM;
-pu8 IMEM;
+
+// NOTE: Links against GLideN64\src\N64.cpp due to conflicts and maintenance efforts
+extern pu8 DMEM;
+extern pu8 IMEM;
 
 NOINLINE void res_S(void)
 {