build: limit assembler version check on x86

The current openssl checks assembler version only x86_64 or ia32
target arch for use of AES-NI, AVX and AVX2.
This requires --openssl-no-asm option during configure when an older
assembler version is found only on x86_64 or ia32.

PR-URL: #20226
Fixes: #19944
Refs: #20217
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

Author: shigeki

BUILDING.md

@@ -94,14 +94,16 @@ Depending on host platform, the selection of toolchains may vary.
 #### OpenSSL asm support
 
 OpenSSL-1.1.0 requires the following asssembler version for use of asm
-support.
+support on x86_64 and ia32.
 
 * gas (GNU assembler) version 2.23 or higher
 * xcode version 5.0 or higher
 * llvm version 3.3 or higher
 * nasm version 2.10 or higher in Windows
 
-Otherwise, `--openssl-no-asm` is added with warning in configure.
+Otherwise `configure` will fail with an error. This can be avoided by
+either providing a newer assembler as per the list above or by
+using the `--openssl-no-asm` flag.
 
 *Note:* The forthcoming OpenSSL-1.1.1 will require higher
  version. Please refer

configure

@@ -1106,6 +1106,8 @@ def configure_openssl(o):
       o['defines'] += ['NODE_WITHOUT_NODE_OPTIONS']
 
   if not options.shared_openssl and not options.openssl_no_asm:
+    is_x86 = 'x64' in variables['target_arch'] or 'ia32' in variables['target_arch']
+
     # supported asm compiler for AVX2. See https://github.com/openssl/openssl/
     # blob/OpenSSL_1_1_0-stable/crypto/modes/asm/aesni-gcm-x86_64.pl#L52-L69
     openssl110_asm_supported = \
@@ -1114,7 +1116,7 @@ def configure_openssl(o):
       ('llvm_version' in variables and float(variables['llvm_version']) >= 3.3) or \
       ('nasm_version' in variables and float(variables['nasm_version']) >= 2.10)
 
-    if not openssl110_asm_supported:
+    if is_x86 and not openssl110_asm_supported:
       error('''Did not find a new enough assembler, install one or build with
        --openssl-no-asm.
        Please refer to BUILDING.md''')