Fix a few linker issues with the eval lib.

src/libprojectM/CMakeLists.txt

@@ -92,6 +92,8 @@ target_include_directories(projectM
         )
 
 target_link_libraries(projectM
+        PRIVATE
+        projectM::Eval
         PUBLIC
         ${PROJECTM_OPENGL_LIBRARIES}
         libprojectM::API

src/libprojectM/MilkdropPreset/CMakeLists.txt

@@ -51,6 +51,7 @@ add_library(MilkdropPreset OBJECT
         WaveformPerFrameContext.hpp
         WaveformPerPointContext.cpp
         WaveformPerPointContext.hpp
+        EvalLibMutex.cpp
         )
 
 target_include_directories(MilkdropPreset

src/libprojectM/MilkdropPreset/EvalLibMutex.cpp

@@ -0,0 +1,4 @@
+#include <projectm-eval.h>
+
+void projectm_eval_memory_host_lock_mutex() {}
+void projectm_eval_memory_host_unlock_mutex() {}