Update Makefile: adjust linker flags for Linux and test target

Author: Gioee

Makefile

@@ -64,7 +64,7 @@ else ifeq ($(PLATFORM),isim)
     CFLAGS += -arch x86_64 -arch arm64 $(SDK)
 else # linux
     TARGET := $(DIST_DIR)/js.so
-    LDFLAGS := -shared
+    LDFLAGS := -lm -shared
 endif
 
 # Object files
@@ -131,7 +131,7 @@ endif
 
 # Compile test target
 $(TEST_TARGET): $(TEST_FILES) $(TARGET)
-	$(CC) $(INCLUDES) $^ -lm -o $@ libs/sqlite3.c -DSQLITE_CORE
+	$(CC) $(INCLUDES) $^ -o $@ libs/sqlite3.c -DSQLITE_CORE
 
 # Testing the extension
 test: $(TARGET) $(TEST_TARGET)