ARMv4 assembly pack: harmonize Thumb-ification of iOS build.

Three modules were left behind in a2859927.
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2617)

crypto/aes/asm/aesv8-armx.pl

@@ -59,9 +59,12 @@ $code=<<___;
 .text
 ___
 $code.=".arch	armv8-a+crypto\n"			if ($flavour =~ /64/);
-$code.=".arch	armv7-a\n.fpu	neon\n.code	32\n"	if ($flavour !~ /64/);
-		#^^^^^^ this is done to simplify adoption by not depending
-		#	on latest binutils.
+$code.=<<___						if ($flavour !~ /64/);
+.arch	armv7-a	// don't confuse not-so-latest binutils with argv8 :-)
+.fpu	neon
+.code	32
+#undef	__thumb2__
+___
 
 # Assembler mnemonics are an eclectic mix of 32- and 64-bit syntax,
 # NEON is mostly 32-bit mnemonics, integer - mostly 64. Goal is to

crypto/armv4cpuid.pl

@@ -27,6 +27,7 @@ $code.=<<___;
 .thumb
 #else
 .code	32
+#undef	__thumb2__
 #endif
 
 .align	5

crypto/modes/asm/ghashv8-armx.pl

@@ -67,7 +67,11 @@ $code=<<___;
 .text
 ___
 $code.=".arch	armv8-a+crypto\n"	if ($flavour =~ /64/);
-$code.=".fpu	neon\n.code	32\n"	if ($flavour !~ /64/);
+$code.=<<___				if ($flavour !~ /64/);
+.fpu	neon
+.code	32
+#undef	__thumb2__
+___
 
 ################################################################################
 # void gcm_init_v8(u128 Htable[16],const u64 H[2]);