Define DLL_ONLY for all configurations; fix vm_x86.c guard

Add unconditional ItemDefinitionGroup in quake3.vcxproj to define DLL_ONLY
for all configurations, disabling QVM interpreter/JIT in favour of DLLs.

Fix vm_x86.c: VM_Compile was outside the #ifndef DLL_ONLY guard while
VM_CallCompiled was inside it, causing a duplicate symbol link error.
Extend the guard to cover VM_Compile as well.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

code/qcommon/vm_x86.c

@@ -396,6 +396,7 @@ qboolean EmitMovEBXEDI(vm_t *vm, int andit) {
 VM_Compile
 =================
 */
+#ifndef DLL_ONLY // bk010215 - for DLL_ONLY dedicated servers/builds w/o VM
 void VM_Compile( vm_t *vm, vmHeader_t *header ) {
 	int		op;
 	int		maxLength;
@@ -1083,6 +1084,7 @@ void VM_Compile( vm_t *vm, vmHeader_t *header ) {
 #endif
 
 }
+#endif // !DLL_ONLY
 
 /*
 ==============

code/quake3.vcxproj

@@ -137,6 +137,11 @@
     <IntDir>.\Debug_TA\</IntDir>
     <LinkIncremental>true</LinkIncremental>
   </PropertyGroup>
+  <ItemDefinitionGroup>
+    <ClCompile>
+      <PreprocessorDefinitions>DLL_ONLY;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+    </ClCompile>
+  </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release TA|Win32'">
     <ClCompile>
       <Optimization>MaxSpeed</Optimization>