Fix Linux linking by moving -lm to LDLIBS

Move the -lm flag from CFLAGS to a new LDLIBS variable and place it
at the end of the linker command. This ensures libm is properly linked
on Linux systems.

The linker processes arguments left-to-right, so library flags must
come after source files that reference their symbols. Previously,
-lm appeared before the source file, causing "undefined symbol: sqrtf"
errors on some Linux distributions.

Cherry-picked from upstream PR asg017#252

Co-Authored-By: wardviaene <[email protected]>

Author: vlasky

Makefile

@@ -31,7 +31,7 @@ endif
 
 ifdef CONFIG_LINUX
 LOADABLE_EXTENSION=so
-CFLAGS += -lm
+LDLIBS += -lm
 endif
 
 ifdef CONFIG_WINDOWS
@@ -102,7 +102,8 @@ $(TARGET_LOADABLE): sqlite-vec.c sqlite-vec.h $(prefix)
 		-Ivendor/ \
 		-O3 \
 		$(CFLAGS) \
-		$< -o $@
+		$< -o $@ \
+		$(LDLIBS)
 
 $(TARGET_STATIC): sqlite-vec.c sqlite-vec.h $(prefix) $(OBJS_DIR)
 	$(CC) -Ivendor/ $(CFLAGS) -DSQLITE_CORE -DSQLITE_VEC_STATIC \