package/gcc: fix libgcc build for xtensa

xtensa libgcc can't be built with -mtext-section-literals flag, now
coming from TARGET_CFLAGS, because it needs to emit literals to
.init/.fini sections, which is not currently supported.

Filter -mtext-section-literals flag out of GCC_COMMON_TARGET_CFLAGS.

Suggested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/gcc/gcc.mk

@@ -112,6 +112,13 @@ GCC_COMMON_TARGET_CXXFLAGS = $(filter-out -Os,$(GCC_COMMON_TARGET_CXXFLAGS))
 endif
 endif
 
+# Xtensa libgcc can't be built with -mtext-section-literals
+# because of the trick used to generate .init/.fini sections.
+ifeq ($(BR2_xtensa),y)
+GCC_COMMON_TARGET_CFLAGS = $(filter-out -mtext-section-literals,$(TARGET_CFLAGS))
+GCC_COMMON_TARGET_CXXFLAGS = $(filter-out -mtext-section-literals,$(TARGET_CXXFLAGS))
+endif
+
 # Propagate options used for target software building to GCC target libs
 HOST_GCC_COMMON_CONF_ENV += CFLAGS_FOR_TARGET="$(GCC_COMMON_TARGET_CFLAGS)"
 HOST_GCC_COMMON_CONF_ENV += CXXFLAGS_FOR_TARGET="$(GCC_COMMON_TARGET_CXXFLAGS)"