x64: Migrate brff and I128 branching instructions to ISLE (#4599)

https://github.com/bytecodealliance/wasmtime/pull/4599

cranelift/filetests/filetests/runtests/fcmp.clif

@@ -0,0 +1,62 @@
+test run
+target aarch64
+target s390x
+target x86_64
+
+function %fcmp_eq(f64, f64) -> b1 {
+block0(v0: f64, v1: f64):
+    v2 = fcmp eq v0, v1
+    return v2
+}
+
+; run: %fcmp_eq(0x1.0, 0x1.0) == true
+; run: %fcmp_eq(0x1.0, 0x0.0) == false
+
+function %fcmp_ne(f64, f64) -> b1 {
+block0(v0: f64, v1: f64):
+    v2 = fcmp ne v0, v1
+    return v2
+}
+
+; run: %fcmp_ne(0x1.0, 0x1.0) == false
+; run: %fcmp_ne(0x1.0, 0x0.0) == true
+
+function %fcmp_lt(f64, f64) -> b1 {
+block0(v0: f64, v1: f64):
+    v2 = fcmp lt v0, v1
+    return v2
+}
+
+; run: %fcmp_lt(0x1.0, 0x1.0) == false
+; run: %fcmp_lt(0x1.0, 0x0.0) == false
+; run: %fcmp_lt(0x1.0, 0x2.3) == true
+
+function %fcmp_le(f64, f64) -> b1 {
+block0(v0: f64, v1: f64):
+    v2 = fcmp le v0, v1
+    return v2
+}
+
+; run: %fcmp_le(0x1.0, 0x1.0) == true
+; run: %fcmp_le(0x1.0, 0x0.0) == false
+; run: %fcmp_le(0x1.0, 0x2.3) == true
+
+function %fcmp_gt(f64, f64) -> b1 {
+block0(v0: f64, v1: f64):
+    v2 = fcmp gt v0, v1
+    return v2
+}
+
+; run: %fcmp_gt(0x1.0, 0x1.0) == false
+; run: %fcmp_gt(0x1.0, 0x0.0) == true
+; run: %fcmp_gt(0x1.0, 0x2.3) == false
+
+function %fcmp_ge(f64, f64) -> b1 {
+block0(v0: f64, v1: f64):
+    v2 = fcmp ge v0, v1
+    return v2
+}
+
+; run: %fcmp_ge(0x1.0, 0x1.0) == true
+; run: %fcmp_ge(0x1.0, 0x0.0) == true
+; run: %fcmp_ge(0x1.0, 0x2.3) == false