crypto/internal/fips: avoid some non-relocatable global initializers

In normal code,

	var x = []int{...}

will be laid out by the linker, but in FIPS packages, the slice
assignment has to be deferred to init time to avoid a global
data relocation. We can avoid the init time work by writing

	var x = [...]int{...}

instead. Do that.

For #69536.

Change-Id: Ie3c1d25af3f79182ee254014e49d3711038aa327
Reviewed-on: https://go-review.googlesource.com/c/go/+/625815
Reviewed-by: Filippo Valsorda <filippo@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

src/crypto/internal/fips/sha256/sha256block.go

@@ -10,7 +10,7 @@ package sha256
 
 import "math/bits"
 
-var _K = []uint32{
+var _K = [...]uint32{
 	0x428a2f98,
 	0x71374491,
 	0xb5c0fbcf,

src/crypto/internal/fips/sha256/sha256block_arm64.s

@@ -16,7 +16,7 @@ TEXT ·blockSHA2(SB),NOSPLIT,$0
 	MOVD	dig+0(FP), R0                              // Hash value first address
 	MOVD	p_base+8(FP), R1                           // message first address
 	MOVD	p_len+16(FP), R3                           // message length
-	MOVD	·_K+0(SB), R2                              // k constants first address
+	MOVD	$·_K+0(SB), R2                             // k constants first address
 	VLD1	(R0), [V0.S4, V1.S4]                       // load h(a,b,c,d,e,f,g,h)
 	VLD1.P	64(R2), [V16.S4, V17.S4, V18.S4, V19.S4]
 	VLD1.P	64(R2), [V20.S4, V21.S4, V22.S4, V23.S4]

src/crypto/internal/fips/sha256/sha256block_riscv64.s

@@ -151,7 +151,7 @@ TEXT ·block(SB),0,$64-32
 	ADD	X29, X30, X28
 	BEQ	X28, X29, end
 
-	MOV	·_K(SB), X18		// const table
+	MOV	$·_K(SB), X18		// const table
 	ADD	$8, X2, X19		// message schedule
 
 	MOV	dig+0(FP), X20

src/crypto/internal/fips/sha512/_asm/sha512block_amd64_asm.go

@@ -438,7 +438,7 @@ func blockAVX2() {
 func loop0() {
 	Label("loop0")
 
-	_K := NewDataAddr(Symbol{Name: ThatPeskyUnicodeDot + "_K"}, 0)
+	_K := NewDataAddr(Symbol{Name: "$" + ThatPeskyUnicodeDot + "_K"}, 0)
 	MOVQ(_K, RBP)
 
 	// byte swap first 16 dwords

src/crypto/internal/fips/sha512/sha512block.go

@@ -10,7 +10,7 @@ package sha512
 
 import "math/bits"
 
-var _K = []uint64{
+var _K = [...]uint64{
 	0x428a2f98d728ae22,
 	0x7137449123ef65cd,
 	0xb5c0fbcfec4d3b2f,

src/crypto/internal/fips/sha512/sha512block_amd64.s

@@ -4526,7 +4526,7 @@ TEXT ·blockAVX2(SB), NOSPLIT, $56-32
 	VMOVDQU PSHUFFLE_BYTE_FLIP_MASK<>+0(SB), Y9
 
 loop0:
-	MOVQ    ·_K+0(SB), BP
+	MOVQ    $·_K+0(SB), BP
 	VMOVDQU (DI), Y4
 	VPSHUFB Y9, Y4, Y4
 	VMOVDQU 32(DI), Y5

src/crypto/internal/fips/sha512/sha512block_arm64.s

@@ -45,7 +45,7 @@ TEXT ·blockSHA512(SB),NOSPLIT,$0
 	MOVD	dig+0(FP), R0
 	MOVD	p_base+8(FP), R1
 	MOVD	p_len+16(FP), R2
-	MOVD	·_K+0(SB), R3
+	MOVD	$·_K+0(SB), R3
 
 	// long enough to prefetch
 	PRFM	(R3), PLDL3KEEP

src/crypto/internal/fips/sha512/sha512block_riscv64.s

@@ -160,7 +160,7 @@ TEXT ·block(SB),0,$128-32
 	ADD	X29, X30, X28
 	BEQ	X28, X29, end
 
-	MOV	·_K(SB), X18		// const table
+	MOV	$·_K(SB), X18		// const table
 	ADD	$8, X2, X19		// message schedule
 
 	MOV	dig+0(FP), X20