Increase the tolerance for jn and yn

These still fail random tests, e.g.:

    called `Result::unwrap()` on an `Err` value: jn

    Caused by:
        0:
               input:    (1068, -16013.98381387313)
               as hex:   (, -0x1.f46fded9ced39p+13)
               as bits:  (0x0000042c, 0xc0cf46fded9ced39)
               expected: 6.7603314308122506e-6  0x1.c5ad9c102d413p-18 0x3edc5ad9c102d413
               actual:   6.7603314308006335e-6  0x1.c5ad9c1029e80p-18 0x3edc5ad9c1029e80
        1: ulp 13715 > 4000

    Caused by:
        0:
               input:    (195, 42147.94)
               as hex:   (, 0x1.4947e2p+15)
               as bits:  (0x000000c3, 0x4724a3f1)
               expected: -2.13669e-7            -0x1.cad9c6p-23 0xb4656ce3
               actual:   -2.1376937e-7          -0x1.cb10f4p-23 0xb465887a
        1: ulp 7063 > 4000

    Caused by:
        0:
               input:    (194, 740.1916)
               as hex:   (, 0x1.721886p+9)
               as bits:  (0x000000c2, 0x44390c43)
               expected: 1.212096e-6            0x1.455e9ap-20 0x35a2af4d
               actual:   1.2172386e-6           0x1.46c000p-20 0x35a36000
        1: ulp 45235 > 10000

Increase allowed precision to avoid spurious failures.

Author: tgross35

crates/libm-test/src/precision.rs

@@ -523,18 +523,7 @@ fn int_float_common<F1: Float, F2: Float>(
         && actual == F2::ZERO
         && expected == F2::ZERO
     {
-        return XFAIL("mpfr b");
-    }
-
-    // Our bessel functions blow up with large N values
-    if ctx.basis == Musl && (ctx.base_name == BaseName::Jn || ctx.base_name == BaseName::Yn) {
-        if input.0 > 4000 {
-            return XFAIL_NOCHECK;
-        } else if input.0 > 2000 {
-            return CheckAction::AssertWithUlp(20_000);
-        } else if input.0 > 1000 {
-            return CheckAction::AssertWithUlp(4_000);
-        }
+        return XFAIL("we disagree with MPFR on the sign of zero");
     }
 
     // Values near infinity sometimes get cut off for us. `ynf(681, 509.90924) = -inf` but should
@@ -549,6 +538,19 @@ fn int_float_common<F1: Float, F2: Float>(
         return XFAIL_NOCHECK;
     }
 
+    // Our bessel functions blow up with large N values
+    if ctx.basis == Musl && (ctx.base_name == BaseName::Jn || ctx.base_name == BaseName::Yn) {
+        if cfg!(x86_no_sse) {
+            // Precision is especially bad on i586, not worth checking.
+            return XFAIL_NOCHECK;
+        }
+
+        if input.0 > 4000 {
+            return XFAIL_NOCHECK;
+        } else if input.0 > 100 {
+            return CheckAction::AssertWithUlp(1_000_000);
+        }
+    }
     DEFAULT
 }