compiler: build separation runtime with clite

runtime/internal/clite/bitcast/_cast/cast.c

@@ -0,0 +1,17 @@
+typedef union {
+    double d;
+    float  f;
+    long   v;
+} castUnion;
+
+double llgoToFloat64(long v) {
+    castUnion k;
+    k.v = v;
+    return k.d;
+}
+
+float llgoToFloat32(long v) {
+    castUnion k;
+    k.v = v;
+    return k.f;
+}

runtime/internal/clite/bitcast/bitcast.go

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package bitcast
+
+import _ "unsafe"
+
+const (
+	LLGoFiles   = "_cast/cast.c"
+	LLGoPackage = "link"
+)
+
+//go:linkname ToFloat64 C.llgoToFloat64
+func ToFloat64(v uintptr) float64
+
+//go:linkname ToFloat32 C.llgoToFloat32
+func ToFloat32(v uintptr) float32