Fix bug where 1.0 == big(1//0) throws (#59715)

Fixup for #58217
Found and fix proposed by Eric Demer

Author: LilithHafner

base/rational.jl

@@ -443,7 +443,7 @@ fma(x::Rational, y::Rational, z::Rational) = x*y+z
 
 function ==(x::AbstractFloat, q::Rational)
     if isfinite(x)
-        (count_ones(q.den) == 1) & (ldexp(x, top_set_bit(q.den-1)) == q.num)
+        (count_ones(q.den) == 1) && (ldexp(x, top_set_bit(q.den-1)) == q.num)
     else
         x == q.num/q.den
     end

test/rational.jl

@@ -853,7 +853,9 @@ end
     end
 end
 
-@testset "Float16 comparison" begin
+@testset "Float-Rational comparison" begin
     @test Float16(6.0e-8) == big(1//16777216) == 1//16777216
     @test Float16(6.0e-8) == 1//16777216
+    @test 1.0 != big(1//0)
+    @test Inf == big(1//0)
 end