feat: add software floating point package

gnovm/pkg/gnolang/internal/softfloat/copy.sh

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+# softfloat64.go:
+# - add header
+# - change package name
+cat > runtime_softfloat64.go << EOF
+// Code generated by copy.sh. DO NOT EDIT.
+// This file is copied from \$GOROOT/src/runtime/softfloat64.go.
+// It is the software floating point implementation used by the Go runtime.
+
+EOF
+cat "$GOROOT/src/runtime/softfloat64.go" >> ./runtime_softfloat64.go
+sed -i 's/^package runtime$/package softfloat/' runtime_softfloat64.go
+
+# softfloat64_test.go:
+# - add header
+# - change package name
+# - change import to right package
+# - change GOARCH to runtime.GOARCH, and import the "runtime" package
+cat > runtime_softfloat64_test.go << EOF
+// Code generated by copy.sh. DO NOT EDIT.
+// This file is copied from \$GOROOT/src/runtime/softfloat64_test.go.
+// It is the tests for the software floating point implementation
+// used by the Go runtime.
+
+EOF
+cat "$GOROOT/src/runtime/softfloat64_test.go" >> ./runtime_softfloat64_test.go
+sed -i 's/^package runtime_test$/package softfloat_test/
+s#^\t\. "runtime"$#\t. "github.com/gnolang/gno/gnovm/pkg/gnolang/internal/softfloat"#
+s/GOARCH/runtime.GOARCH/g
+16a\
+    "runtime"' runtime_softfloat64_test.go