x86emul/test: generate non-pie executable for 64bit builds

PIE may (and commonly will) result in the binary being loaded above
the 4Gb boundary, which can't work with at least the VZEROUPPER compat
mode test.

Add -fno-PIE and -no-pie when appropriate so that gcc won't generate a
PIE executable.

Reported-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

tools/tests/x86_emulator/Makefile

@@ -76,7 +76,7 @@ $(addsuffix .c,$(SIMD)) $(addsuffix -avx.c,$(filter sse%,$(SIMD))):
 	ln -sf simd.c $@
 
 $(TARGET): x86_emulate.o test_x86_emulator.o
-	$(HOSTCC) -o $@ $^
+	$(HOSTCC) $(HOSTCFLAGS) -o $@ $^
 
 .PHONY: clean
 clean:
@@ -98,7 +98,9 @@ asm:
 
 asm/%: asm ;
 
-HOSTCFLAGS += $(CFLAGS_xeninclude) -I.
+HOSTCFLAGS-x86_64 := -fno-PIE
+$(call cc-option-add,HOSTCFLAGS-x86_64,HOSTCC,-no-pie)
+HOSTCFLAGS += $(CFLAGS_xeninclude) -I. $(HOSTCFLAGS-$(XEN_COMPILE_ARCH))
 
 x86.h := asm/x86-vendors.h asm/x86-defns.h asm/msr-index.h
 x86_emulate.h := x86_emulate.h x86_emulate/x86_emulate.h $(x86.h)