Don't use Int32 indices in rand kernels. (#1969)

Author: maleadt

src/random.jl

@@ -51,7 +51,7 @@ function Random.rand!(rng::RNG, A::AnyCuArray)
         # grid-stride loop
         threadId = threadIdx().x
         window = blockDim().x * gridDim().x
-        offset = (blockIdx().x - 1i32) * blockDim().x
+        offset = (blockIdx().x - 1) * blockDim().x
         while offset < length(A)
             i = threadId + offset
             if i <= length(A)
@@ -87,8 +87,8 @@ function Random.randn!(rng::RNG, A::AnyCuArray{<:Union{AbstractFloat,Complex{<:A
 
         # grid-stride loop
         threadId = threadIdx().x
-        window = (blockDim().x - 1i32) * gridDim().x
-        offset = (blockIdx().x - 1i32) * blockDim().x
+        window = (blockDim().x - 1) * gridDim().x
+        offset = (blockIdx().x - 1) * blockDim().x
         while offset < length(A)
             i = threadId + offset
             j = threadId + offset + window
@@ -120,8 +120,8 @@ function Random.randn!(rng::RNG, A::AnyCuArray{<:Union{AbstractFloat,Complex{<:A
 
         # grid-stride loop
         threadId = threadIdx().x
-        window = (blockDim().x - 1i32) * gridDim().x
-        offset = (blockIdx().x - 1i32) * blockDim().x
+        window = (blockDim().x - 1) * gridDim().x
+        offset = (blockIdx().x - 1) * blockDim().x
         while offset < length(A)
             i = threadId + offset
             if i <= length(A)