package/brotli: workaround m68k build issues

On m68k building with optimizations  results in failures such as:

/tmp/cckiMnG5.s: Assembler messages:
/tmp/cckiMnG5.s:142572: Error: value -39206 out of range
/tmp/cckiMnG5.s:142629: Error: value -40282 out of range
/tmp/cckiMnG5.s:146408: Error: value -53294 out of range
/tmp/cckiMnG5.s:159014: Error: value -39206 out of range
/tmp/cckiMnG5.s:159071: Error: value -40282 out of range
/tmp/cckiMnG5.s:162850: Error: value -53294 out of range
/tmp/cckiMnG5.s:175456: Error: value -39206 out of range
/tmp/cckiMnG5.s:175513: Error: value -40282 out of range
/tmp/cckiMnG5.s:179292: Error: value -53294 out of range
/tmp/cckiMnG5.s:191898: Error: value -39206 out of range
/tmp/cckiMnG5.s:191955: Error: value -40282 out of range
/tmp/cckiMnG5.s:195734: Error: value -53294 out of range

These only appear when building with -O2, the smaller code generated
with -Os does not cause trouble, so workaround by using that.

Fixes:

  http://autobuild.buildroot.net/results/2f222d5a86b4237b81ca31dba89f58b0e6e879db/

Signed-off-by: Adrian Perez de Castro <aperez@igalia.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/brotli/brotli.mk

@@ -21,6 +21,12 @@ ifeq ($(BR2_TOOLCHAIN_HAS_GCC_BUG_68485),y)
 BROTLI_CFLAGS += -O0
 endif
 
+# Workaround "Error: value -1234 out of range" assembler issues
+# when building with optimizations.
+ifeq ($(BR2_m68k),y)
+BROTLI_CFLAGS += -Os
+endif
+
 BROTLI_CONF_OPTS += -DCMAKE_C_FLAGS="$(BROTLI_CFLAGS)"
 
 $(eval $(cmake-package))