cmd/compile: correct wasmexport result type checking

The function resultsToWasmFields was originally for only
wasmimport. I adopted it for wasmexport as well, but forgot to
update a few places that were wasmimport-specific. This leads to
compiler panic if an invalid result type is passed, and also
unsafe.Pointer not actually supported. This CL fixes it.

Updates golang#65199.

Change-Id: I9bbd7154b70422504994840ff541c39ee596ee8f
Reviewed-on: https://go-review.googlesource.com/c/go/+/611315
Reviewed-by: Michael Knyszek <[email protected]>
Reviewed-by: Achille Roussel <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: cherrymui

src/cmd/compile/internal/ssagen/abi.go

@@ -451,8 +451,10 @@ func resultsToWasmFields(f *ir.Func, pragma string, result *abi.ABIParamResultIn
 			wfs[i].Type = obj.WasmF32
 		case types.TFLOAT64:
 			wfs[i].Type = obj.WasmF64
+		case types.TUNSAFEPTR:
+			wfs[i].Type = obj.WasmPtr
 		default:
-			base.ErrorfAt(f.Pos(), 0, "go:wasmimport %s %s: unsupported result type %s", f.WasmImport.Module, f.WasmImport.Name, t.String())
+			base.ErrorfAt(f.Pos(), 0, "%s: unsupported result type %s", pragma, t.String())
 		}
 		wfs[i].Offset = p.FrameOffset(result)
 	}

test/wasmexport2.go

@@ -24,6 +24,9 @@ func good2(MyInt32) {} // named type is ok
 //go:wasmexport good3
 func good3() int32 { return 0 } // one result is ok
 
+//go:wasmexport good4
+func good4() unsafe.Pointer { return nil } // one result is ok
+
 //go:wasmexport bad1
 func bad1(string) {} // ERROR "go:wasmexport: unsupported parameter type"
 
@@ -54,5 +57,11 @@ func bad7(*S) {} // ERROR "go:wasmexport: unsupported parameter type"
 //go:wasmexport bad8
 func bad8([4]int32) {} // ERROR "go:wasmexport: unsupported parameter type"
 
+//go:wasmexport bad9
+func bad9() bool { return false } // ERROR "go:wasmexport: unsupported result type"
+
+//go:wasmexport bad10
+func bad10() *byte { return nil } // ERROR "go:wasmexport: unsupported result type"
+
 //go:wasmexport toomanyresults
 func toomanyresults() (int32, int32) { return 0, 0 } // ERROR "go:wasmexport: too many return values"