This patch provides a workaround for https://github.com/openssl/openssl/issues/15587

This patch changes Montgomery squaring implementation for SPARCv9
so that it uses less optimized code path (within code path that is
already heavily optimized and written in handcrafted assembly).
Basically, instead of using dedicated Montgomery squaring procedure ( A == B ),
it will use the generic Montgomery multiplication procedure ( A != B ).

This results in performance degradation, until proper fix is determined.
When calling ECDSA_sign()/ECDSA_verify() back to back in FIPS mode with the
NID_secp521r1 curve, using 64-bit program on a LDOM with 16 SPARC-M7 CPUs on a
SPARC T7-1 machine, the performance degradation was 5 percent on average.

--- openssl-3.4.0/crypto/bn/asm/sparcv9-mont.pl.orig
+++ openssl-3.4.0/crypto/bn/asm/sparcv9-mont.pl
@@ -117,7 +117,7 @@
 	ld	[$np],$car1		! np[0]
 	sub	%o7,$bias,%sp		! alloca
 	ld	[$np+4],$npj		! np[1]
-	be,pt	SIZE_T_CC,.Lbn_sqr_mont
+	nop				! disable bn_sqr_mont for now
 	mov	12,$j
 
 	mulx	$car0,$mul0,$car0	! ap[0]*bp[0]