package/x264: disable assembly code on x86 + musl + PIC/PIE

The x264 package uses large amounts of non-PIC assembly code
(e.g. common/x86/dct-a.asm), which results in textrels, which aren't
supported by musl-libc's dynamic linker.

Disable x264's assembly code when compiling for x86 with PIC/PIE and
musl-libc to avoid this particular incompatibility.

Reported-by: Yann Morin <yann.morin@orange.com>
Fixes: https://lore.kernel.org/buildroot/ZrsirnrvgsEIpAJI@tl-lnx-nyma7486-2/
Signed-off-by: J. Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/x264/x264.mk

@@ -14,9 +14,15 @@ X264_INSTALL_STAGING = YES
 X264_CONF_OPTS = --disable-avs --disable-lavf --disable-swscale
 
 ifeq ($(BR2_i386)$(BR2_x86_64),y)
+ifeq ($(BR2_TOOLCHAIN_USES_MUSL)$(BR2_PIC_PIE),yy)
+# libx264 uses large amounts of non-pic assembly code, resulting in text
+# section relocations, which are not supported on musl-libc's ld.so.
+X264_CONF_OPTS += --disable-asm
+else
 # nasm needed for assembly files
 X264_DEPENDENCIES += host-nasm
 X264_CONF_ENV += AS="$(HOST_DIR)/bin/nasm"
+endif
 else ifeq ($(BR2_ARM_CPU_ARMV7A)$(BR2_aarch64),y)
 # We need to pass gcc as AS, because the ARM assembly files have to be
 # preprocessed