aarch64: Add -moverride=tune=no_ldp_stp_qregs to TARGET_CFLAGS

From Zephyr arch/arm64/core/CMakeLists.txt:

 GCC may generate ldp/stp instructions with the Advanced SIMD Qn registers for
 consecutive 32-byte loads and stores. Saving and restoring the Advanced SIMD
 context is very expensive, and it is preferable to keep it turned off by not
 emitting these instructions for better context switching performance.

Also, if these instructions happen from an ISR, they will trap and
appear to leave interrupts disabled afterwards. That bug should be fixed.

Signed-off-by: Keith Packard <[email protected]>

Author: keith-packard

configs/aarch64-zephyr-elf.config

@@ -6,6 +6,7 @@ CT_ARCH_ARM=y
 CT_MULTILIB=y
 CT_ARCH_64=y
 CT_TARGET_VENDOR="zephyr"
+CT_TARGET_CFLAGS="-moverride=tune=no_ldp_stp_qregs"
 CT_BINUTILS_SRC_CUSTOM=y
 CT_BINUTILS_CUSTOM_LOCATION="${GITHUB_WORKSPACE}/binutils"
 CT_NEWLIB_SRC_CUSTOM=y