add compiler flag -msse2 for aws-lc on x86 (#291)

Author: TingDaoK

builder/imports/awslc.py

@@ -54,8 +54,11 @@ def __init__(self, **kwargs):
             **kwargs)
 
     def cmake_args(self, env):
+        result = super().cmake_args(env)
         if env.spec.compiler == 'gcc' and env.spec.compiler_version.startswith('4.'):
             # Disable AVX512 on old GCC versions for aws-lc as they dont support AVX512 instructions used by aws-lc
-            return super().cmake_args(env) + ['-DMY_ASSEMBLER_IS_TOO_OLD_FOR_512AVX=ON']
-
-        return super().cmake_args(env)
+            result = result + ['-DMY_ASSEMBLER_IS_TOO_OLD_FOR_512AVX=ON']
+        if env.spec.arch == 'x86':
+            # Add -msse2 for compiler on x86.
+            result = result + ['-DCMAKE_C_FLAGS=-msse2']
+        return result