tdraudio: add irq_enable flag, add pcmaudio library

runtime: disable interrupts on PTERM
stdlib: check for error state in FileSize

examples/pcmtest.pas

@@ -0,0 +1,47 @@
+{$H1536}
+program pcmtest;
+uses pcmaudio;
+
+var filename:string;
+    buf:SndBufPtr;
+    f:file;
+    size:integer;
+    i:integer;
+    c:char;
+    sampleRate:integer;
+    err:integer;
+begin
+	if ParamCount > 0 then
+		filename := ParamStr(1)
+	else
+	begin
+		write('Filename> ');
+		readln(filename);
+	end;
+
+	err := 1;
+	if ParamCount > 1 then
+		val(ParamStr(2),sampleRate, err);
+
+	if err <> 0 then
+		sampleRate := 16000;
+
+	open(f, filename, ModeReadOnly);
+	size := FileSize(f);
+	new(buf, size);
+
+	buf^ := '';
+	write('Reading ', size, ' bytes...');
+	for i := 1 to size do
+	begin
+		read(f,c);
+		AppendChar(buf^,c);
+	end;
+	writeln;
+
+	close(f);
+
+	PlaySample(buf, sampleRate);
+
+	dispose(buf);
+end.