Revert "math/rand/v2: add ChaCha8"

This reverts commit 6382893.

Reason for revert: Causes failures on big endian platforms and riscv64.
Possibly a bug in the generic implementation.

For golang#64284.
For golang#64285.

Change-Id: Ic1bb8533d9641fae28d0337b36d434b9a575cd7e
Reviewed-on: https://go-review.googlesource.com/c/go/+/543895
Reviewed-by: Heschi Kreinick <heschi@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
TryBot-Bypass: Michael Knyszek <mknyszek@google.com>

Author: mknyszek

api/next/61716.txt

@@ -9,7 +9,6 @@ pkg math/rand/v2, func Int64N(int64) int64 #61716
 pkg math/rand/v2, func IntN(int) int #61716
 pkg math/rand/v2, func N[$0 intType]($0) $0 #61716
 pkg math/rand/v2, func New(Source) *Rand #61716
-pkg math/rand/v2, func NewChaCha8([32]uint8) *ChaCha8 #61716
 pkg math/rand/v2, func NewPCG(uint64, uint64) *PCG #61716
 pkg math/rand/v2, func NewZipf(*Rand, float64, float64, uint64) *Zipf #61716
 pkg math/rand/v2, func NormFloat64() float64 #61716
@@ -20,10 +19,6 @@ pkg math/rand/v2, func Uint32N(uint32) uint32 #61716
 pkg math/rand/v2, func Uint64() uint64 #61716
 pkg math/rand/v2, func Uint64N(uint64) uint64 #61716
 pkg math/rand/v2, func UintN(uint) uint #61716
-pkg math/rand/v2, method (*ChaCha8) MarshalBinary() ([]uint8, error) #61716
-pkg math/rand/v2, method (*ChaCha8) Seed([32]uint8) #61716
-pkg math/rand/v2, method (*ChaCha8) Uint64() uint64 #61716
-pkg math/rand/v2, method (*ChaCha8) UnmarshalBinary([]uint8) error #61716
 pkg math/rand/v2, method (*PCG) MarshalBinary() ([]uint8, error) #61716
 pkg math/rand/v2, method (*PCG) Seed(uint64, uint64) #61716
 pkg math/rand/v2, method (*PCG) Uint64() uint64 #61716
@@ -46,7 +41,6 @@ pkg math/rand/v2, method (*Rand) Uint64() uint64 #61716
 pkg math/rand/v2, method (*Rand) Uint64N(uint64) uint64 #61716
 pkg math/rand/v2, method (*Rand) UintN(uint) uint #61716
 pkg math/rand/v2, method (*Zipf) Uint64() uint64 #61716
-pkg math/rand/v2, type ChaCha8 struct #61716
 pkg math/rand/v2, type PCG struct #61716
 pkg math/rand/v2, type Rand struct #61716
 pkg math/rand/v2, type Source interface { Uint64 } #61716

src/go/build/deps_test.go

@@ -55,17 +55,10 @@ var depsRules = `
 
 	unsafe < maps;
 
-	unsafe < internal/chacha8rand;
-
 	# RUNTIME is the core runtime group of packages, all of them very light-weight.
-	internal/abi,
-	internal/chacha8rand,
-	internal/coverage/rtcov,
-	internal/cpu,
-	internal/goarch,
-	internal/godebugs,
-	internal/goexperiment,
-	internal/goos
+	internal/abi, internal/cpu, internal/goarch,
+	internal/coverage/rtcov, internal/godebugs, internal/goexperiment,
+	internal/goos, unsafe
 	< internal/bytealg
 	< internal/itoa
 	< internal/unsafeheader