Add AArch64 Big Endian Variants using FVP models (#554)

This patch add new aarch64 big endian library variants.
 1. aarch64_be
 2. aarch64_be_exn_rtti

QEMU's doesn't have big-endian support in the release binaries. so need
to use FVPs to test those libraries.

Author: simpal01

arm-multilib/json/multilib.json

@@ -10,6 +10,16 @@
             "json": "aarch64a.json",
             "flags": "--target=aarch64-unknown-none-elf -fno-exceptions -fno-rtti"
         },
+        {
+            "variant": "aarch64a_be_exn_rtti",
+            "json": "aarch64a_be_exn_rtti.json",
+            "flags": "--target=aarch64_be-unknown-none-elf"
+        },
+        {
+            "variant": "aarch64a_be",
+            "json": "aarch64a_be.json",
+            "flags": "--target=aarch64_be-unknown-none-elf -fno-exceptions -fno-rtti"
+        },
         {
             "variant": "armv4t_exn_rtti",
             "json": "armv4t_exn_rtti.json",

arm-multilib/json/variants/aarch64a_be.json

@@ -0,0 +1,40 @@
+{
+    "args": {
+        "common": {
+            "TARGET_ARCH": "aarch64a",
+            "VARIANT": "aarch64a_be",
+            "COMPILE_FLAGS": "-march=armv8-a -mbig-endian",
+            "ENABLE_EXCEPTIONS": "OFF",
+            "ENABLE_RTTI": "OFF",
+            "TEST_EXECUTOR": "fvp",
+            "FVP_MODEL": "aem-a",
+            "FVP_CONFIG": "v8a-aarch64 big-endian",
+            "BOOT_FLASH_ADDRESS": "0x80000000",
+            "BOOT_FLASH_SIZE": "0x1000",
+            "FLASH_ADDRESS": "0x80001000",
+            "FLASH_SIZE": "0xfff000",
+            "RAM_ADDRESS": "0x81000000",
+            "RAM_SIZE": "0x1000000",
+            "STACK_SIZE": "8K"
+        },
+        "picolibc": {
+            "PICOLIBC_BUILD_TYPE": "release",
+            "ENABLE_CXX_LIBS": "ON",
+            "ENABLE_LIBC_TESTS": "ON",
+            "ENABLE_COMPILER_RT_TESTS": "OFF",
+            "ENABLE_LIBCXX_TESTS": "OFF"
+        },
+        "newlib": {
+            "ENABLE_CXX_LIBS": "ON",
+            "ENABLE_LIBC_TESTS": "OFF",
+            "ENABLE_COMPILER_RT_TESTS": "OFF",
+            "ENABLE_LIBCXX_TESTS": "OFF"
+        },
+        "llvmlibc": {
+            "ENABLE_CXX_LIBS": "OFF",
+            "ENABLE_LIBC_TESTS": "OFF",
+            "ENABLE_COMPILER_RT_TESTS": "OFF",
+            "ENABLE_LIBCXX_TESTS": "OFF"
+        }
+    }
+}

arm-multilib/json/variants/aarch64a_be_exn_rtti.json

@@ -0,0 +1,40 @@
+{
+    "args": {
+        "common": {
+            "TARGET_ARCH": "aarch64a",
+            "VARIANT": "aarch64a_be_exn_rtti",
+            "COMPILE_FLAGS": "-march=armv8-a -mbig-endian",
+            "ENABLE_EXCEPTIONS": "ON",
+            "ENABLE_RTTI": "ON",
+            "TEST_EXECUTOR": "fvp",
+            "FVP_MODEL": "aem-a",
+            "FVP_CONFIG": "v8a-aarch64 big-endian",
+            "BOOT_FLASH_ADDRESS": "0x80000000",
+            "BOOT_FLASH_SIZE": "0x1000",
+            "FLASH_ADDRESS": "0x80001000",
+            "FLASH_SIZE": "0xfff000",
+            "RAM_ADDRESS": "0x81000000",
+            "RAM_SIZE": "0x1000000",
+            "STACK_SIZE": "8K"
+        },
+        "picolibc": {
+            "PICOLIBC_BUILD_TYPE": "release",
+            "ENABLE_CXX_LIBS": "ON",
+            "ENABLE_LIBC_TESTS": "ON",
+            "ENABLE_COMPILER_RT_TESTS": "OFF",
+            "ENABLE_LIBCXX_TESTS": "OFF"
+        },
+        "newlib": {
+            "ENABLE_CXX_LIBS": "ON",
+            "ENABLE_LIBC_TESTS": "OFF",
+            "ENABLE_COMPILER_RT_TESTS": "OFF",
+            "ENABLE_LIBCXX_TESTS": "OFF"
+        },
+        "llvmlibc": {
+            "ENABLE_CXX_LIBS": "OFF",
+            "ENABLE_LIBC_TESTS": "OFF",
+            "ENABLE_COMPILER_RT_TESTS": "OFF",
+            "ENABLE_LIBCXX_TESTS": "OFF"
+        }
+    }
+}

fvp/config/big-endian.cfg

@@ -0,0 +1 @@
+cluster0.cpu0.CFGEND=1