Fix type inferencing, syntax highlighting and code navigation for macro methods

[eric-milles]

Consider the following (taken from https://docs.groovy-lang.org/latest/html/documentation/#_macro_methods):

src/main/macros/MacroMethod.groovy

package macros

import groovy.transform.*
import org.codehaus.groovy.ast.expr.*
import org.codehaus.groovy.macro.runtime.*

import static org.codehaus.groovy.ast.tools.GeneralUtils.*

@AutoFinal @CompileStatic
class MacroMethod {
  @Macro
  static Expression safe(MacroContext ctxt, MethodCallExpression call) {
    ternaryX(notNullX(call.objectExpression), call, nullX())
  }
}

META-INF/groovy/org.codehaus.groovy.runtime.ExtensionModule

moduleName=whatever
moduleVersion=1.0.0-SNAPSHOT
extensionClasses=macros.MacroMethod

script.groovy (in another project)

def objExp = null
def hashCode = safe(objExp.hashCode())
assert safe(hashCode.toString()) == null

Calls to macro method "safe" have default highlighting and make reference to MacroStub. It would be nice to have similar coloration to extension methods (DGMs) and have code navigation back to the actual macro method.

[eric-milles]

Notes: no traces of the original method call expression is left in the AST after the macro method is processed. And groovy-macro cannot be patched since it is not shipped with the eclipse tools.