tests/tcg: enable building for i386

While you can construct a compile command that does work using the
x86_64 host compiler that most people use this is flakey. Different
distros handle this is different ways so we default to using a known
good i386 compiler via docker.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>

tests/tcg/i386/Makefile.include

+#
+# Makefile.include for all i386
+#
+# There is enough brokeness in x86_64 compilers that we don't default
+# to using the x86_64 system compiler for i386 binaries.
+#
+
+DOCKER_IMAGE=fedora-i386-cross
+DOCKER_CROSS_COMPILER=gcc

tests/tcg/i386/Makefile.target

@@ -28,3 +28,10 @@ hello-i386: LDFLAGS+=-nostdlib
 test-i386: test-i386.c test-i386-code16.S test-i386-vm86.S test-i386.h test-i386-shift.h test-i386-muldiv.h
 	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ \
 	   $(<D)/test-i386.c $(<D)/test-i386-code16.S $(<D)/test-i386-vm86.S -lm
+
+# Specialist test runners
+run-runcom: runcom pi_10.com
+	$(call quiet-command, $(QEMU) ./runcom $(I386_SRC)/pi_10.com > runcom.out, "TEST", "$< on $(TARGET_NAME)")
+
+# On i386 and x86_64 Linux only supports 4k pages (large pages are a different hack)
+EXTRA_RUNS+=run-test-mmap-4096