Ensure that unsafe_view doesn't check bounds

(cherry picked from commit 32bc971)
ref #20225

and the test from #19555 because it passes, why not

base/subarray.jl

@@ -82,7 +82,7 @@ function unsafe_view{T,N}(A::AbstractArray{T,N}, I::Vararg{ViewIndex,N})
 end
 function unsafe_view{T,N}(V::SubArray{T,N}, I::Vararg{ViewIndex,N})
     @_inline_meta
-    idxs = reindex(V, V.indexes, to_indexes(I...))
+    @inbounds idxs = reindex(V, V.indexes, to_indexes(I...))
     SubArray(V.parent, idxs, map(unsafe_length, (index_shape(V.parent, idxs...))))
 end
 

test/boundscheck_exec.jl

@@ -151,4 +151,32 @@ end
 
 @test B2() == 0
 
+# issue #19554
+function f19554(a)
+    a[][3]
+end
+function f19554_2(a, b)
+    a[][3] = b
+    return a
+end
+a19554 = Ref{Array{Float64}}([1 2; 3 4])
+@test f19554(a19554) === 2.0
+@test f19554_2(a19554, 1) === a19554
+@test a19554[][3] === f19554(a19554) === 1.0
+
+# Ensure unsafe_view doesn't check bounds
+function V1()
+    A = rand(10,10)
+    B = view(A, 4:7, 4:7)
+    C = Base.unsafe_view(B, -2:7, -2:7)
+    @test C == A
+    nothing
+end
+
+if bc_opt == bc_default || bc_opt == bc_off
+    @test V1() == nothing
+else
+    @test_throws BoundsError V1()
+end
+
 end