Removes redundant error handling (#668)

This consolidates to use EBADF in places go uses it in syscalls to
reduce where we formally returned both bool and err. This also removes
the redundant panic type handling as go will already panic with a
similar message.

Signed-off-by: Adrian Cole <adrian@tetrate.io>

runtime.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"context"
 	"errors"
-	"fmt"
 
 	"github.com/tetratelabs/wazero/api"
 	"github.com/tetratelabs/wazero/internal/wasm"
@@ -125,10 +124,7 @@ func NewRuntime() Runtime {
 
 // NewRuntimeWithConfig returns a runtime with the given configuration.
 func NewRuntimeWithConfig(rConfig RuntimeConfig) Runtime {
-	config, ok := rConfig.(*runtimeConfig)
-	if !ok {
-		panic(fmt.Errorf("unsupported wazero.RuntimeConfig implementation: %#v", rConfig))
-	}
+	config := rConfig.(*runtimeConfig)
 	store, ns := wasm.NewStore(config.enabledFeatures, config.newEngine(config.enabledFeatures))
 	return &runtime{
 		store:           store,
@@ -164,11 +160,7 @@ func (r *runtime) CompileModule(ctx context.Context, binary []byte, cConfig Comp
 		return nil, errors.New("binary == nil")
 	}
 
-	config, ok := cConfig.(*compileConfig)
-	if !ok {
-		panic(fmt.Errorf("unsupported wazero.CompileConfig implementation: %#v", cConfig))
-	}
-
+	config := cConfig.(*compileConfig)
 	if len(binary) < 4 || !bytes.Equal(binary[0:4], binaryformat.Magic) {
 		return nil, errors.New("invalid binary")
 	}