package/pixman: fix build failure due to gcc bug 101737

The pixman package exhibits gcc bug 101737 when built for the SH4
architecture with optimization enabled, which causes a build failure.

As done for other packages in Buildroot work around this gcc bug by
setting optimization to -O0 if BR2_TOOLCHAIN_HAS_GCC_BUG_101737=y.
Also let's add PIXMAN_CFLAGS and pass the Codesourcery work around CFLAGS
to it for consistency like we do for the rest of the packages.

Fixes:
http://autobuild.buildroot.net/results/b20/b20869bbb48edb1f0a847ea9e2e1a0462d6350be/

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/pixman/pixman.mk

@@ -44,12 +44,20 @@ ifneq ($(BR2_iwmmxt),y)
 PIXMAN_CONF_OPTS += --disable-arm-iwmmxt
 endif
 
+PIXMAN_CFLAGS = $(TARGET_CFLAGS)
+
 # toolchain gets confused about TLS access through GOT (PIC), so disable TLS
 # movhi	r4, %got_hiadj(%tls_ldo(fast_path_cache))
 # {standard input}:172: Error: bad expression
 ifeq ($(BR2_TOOLCHAIN_EXTERNAL_CODESOURCERY_NIOSII),y)
-PIXMAN_CONF_ENV += CFLAGS="$(TARGET_CFLAGS) -DPIXMAN_NO_TLS"
+PIXMAN_CFLAGS += -DPIXMAN_NO_TLS
+endif
+
+ifeq ($(BR2_TOOLCHAIN_HAS_GCC_BUG_101737),y)
+PIXMAN_CFLAGS += -O0
 endif
 
+PIXMAN_CONF_OPTS += CFLAGS="$(PIXMAN_CFLAGS)"
+
 $(eval $(autotools-package))
 $(eval $(host-autotools-package))