Update Makefile.

removed LDFLAGS:=-lm

removed -g -O3 in CFLAGS

Makefile

 CC:=gcc
-CFLAGS:=-g -O3 -Wextra -pedantic -fsanitize=address
-LDFLAGS:=-lm
+CFLAGS:= -Wextra -pedantic -fsanitize=address
 NAME:=stack
 
 $(NAME): main.o $(NAME).o
-    $(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) -lSDL2
+    $(CC) $(CFLAGS) -o $@ $^ -lSDL2
 
 tests: $(NAME)_tests.o $(NAME).o
-    $(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
+    $(CC) $(CFLAGS) -o $@ $^
 
 $(NAME).o: $(NAME).h