Enable --debug:full on coreclr (#4366)

src/fsharp/CompileOptions.fs

@@ -470,7 +470,13 @@ let SetDebugSwitch (tcConfigB : TcConfigBuilder) (dtype : string option) (s : Op
        | "portable" ->  tcConfigB.portablePDB <- true;  tcConfigB.embeddedPDB <- false; tcConfigB.jitTracking <- true; tcConfigB.ignoreSymbolStoreSequencePoints <- true
        | "pdbonly" ->   tcConfigB.portablePDB <- false; tcConfigB.embeddedPDB <- false; tcConfigB.jitTracking <- false
        | "embedded" ->  tcConfigB.portablePDB <- true;  tcConfigB.embeddedPDB <- true;  tcConfigB.jitTracking <- true; tcConfigB.ignoreSymbolStoreSequencePoints <- true
+#if FX_NO_PDB_WRITER
+       // When building on the coreclr, full means portable
+       | "full" ->      tcConfigB.portablePDB <- true; tcConfigB.embeddedPDB <- false; tcConfigB.jitTracking <- true
+#else
        | "full" ->      tcConfigB.portablePDB <- false; tcConfigB.embeddedPDB <- false; tcConfigB.jitTracking <- true
+#endif
+
        | _ -> error(Error(FSComp.SR.optsUnrecognizedDebugType(s), rangeCmdArgs))
     | None ->           tcConfigB.portablePDB <- false; tcConfigB.embeddedPDB <- false; tcConfigB.jitTracking <- s = OptionSwitch.On;
     tcConfigB.debuginfo <- s = OptionSwitch.On