Support ByRefLike types as Generic parameters

eng/pipelines/common/templates/runtimes/build-test-job.yml

@@ -73,7 +73,7 @@ jobs:
       - ${{ each variable in parameters.variables }}:
         - ${{ variable }}
       - name: liveRuntimeBuildParams
-        value: 'libs.sfx+libs.oob /p:RefOnly=true -c Release -ci'
+        value: 'libs.sfx+libs.oob+clr.iltools /p:RefOnly=true -c Release -ci'
       - name: compilerArg
         value: ''
       - ${{ if and(ne(parameters.osGroup, 'windows'), ne(parameters.compilerName, 'gcc')) }}:

src/coreclr/ilasm/asmparse.y

@@ -68,7 +68,7 @@
 %token UINT_ UINT8_ UINT16_ UINT32_ UINT64_  FLAGS_ CALLCONV_ MDTOKEN_
 %token OBJECT_ STRING_ NULLREF_
         /* misc keywords */
-%token DEFAULT_ CDECL_ VARARG_ STDCALL_ THISCALL_ FASTCALL_ CLASS_
+%token DEFAULT_ CDECL_ VARARG_ STDCALL_ THISCALL_ FASTCALL_ CLASS_ BYREFLIKE_
 %token TYPEDREF_ UNMANAGED_ FINALLY_ HANDLER_ CATCH_ FILTER_ FAULT_
 %token EXTENDS_ IMPLEMENTS_ TO_ AT_ TLS_ TRUE_ FALSE_ _INTERFACEIMPL
 
@@ -486,7 +486,9 @@ typarAttrib             : '+'                               { $$ = gpCovariant;
                         | '-'                               { $$ = gpContravariant; }
                         | CLASS_                            { $$ = gpReferenceTypeConstraint; }
                         | VALUETYPE_                        { $$ = gpNotNullableValueTypeConstraint; }
+                        | BYREFLIKE_                        { $$ = gpAcceptByRefLike; }
                         | _CTOR                             { $$ = gpDefaultConstructorConstraint; }
+                        | FLAGS_ '(' int32 ')'              { $$ = (CorGenericParamAttr)$3; }
                         ;
 
 typarAttribs            : /* EMPTY */                       { $$ = 0; }