[Pal/Makefiles] Force -no-pie when building PAL tests

PAL loader cannot relocate executables. Thus, PIE executables (per
default GCC setting on Ubuntu 18.04) will crash if no other loader
(e.g., Glibc loader) is involved. Since PAL tests are only for
internal testing purposes, we simply make these tests position-
dependent (adding -no-pie to CFLAGS).

Pal/regression/Makefile

@@ -1,7 +1,7 @@
 include ../src/Makefile.Host
 
 CC	= gcc
-CFLAGS	= -Wall -O2 -std=c11 -fno-builtin -nostdlib -mavx \
+CFLAGS	= -Wall -O2 -std=c11 -fno-builtin -nostdlib -mavx -no-pie \
 	  -I../include/pal -I../lib
 
 preloads    = $(patsubst %.c,%,$(wildcard *.so.c))
@@ -53,7 +53,7 @@ ifeq ($(findstring x86_64,$(SYS))$(findstring linux,$(SYS)),x86_64linux)
 $(preloads): %.so: %.so.c ../src/user_shared_start.o \
 	$(graphene_lib) $(pal_lib) ../include/pal/pal.h
 	@echo [ $@ ]
-	@$(CC) -shared -fPIC $(CFLAGS) $^ -o $@
+	@$(CC) -shared -fPIC $(filter-out -no-pie,$(CFLAGS)) $^ -o $@
 
 $(executables): %: %.c ../src/user_start.o \
 	$(graphene_lib) $(pal_lib) $(preloads) ../include/pal/pal.h

Pal/test/Makefile

@@ -1,7 +1,7 @@
 include ../src/Makefile.Host
 
 CC	= gcc
-CFLAGS	= -Wall -O2 -std=c11 -fno-builtin -nostdlib \
+CFLAGS	= -Wall -O2 -std=c11 -fno-builtin -nostdlib -no-pie \
 	  -I../include/pal -I../lib
 
 .PHONY: default