[Build] Remove definition PLUGIN_PATH system-property for I-build tests

All usages of the 'PLUGIN_PATH' system-property in tests have been
removed. Therefore that property and it's defining ANT property
'plugin-path' can be removed.

Author: HannesWell

eclipse.platform.releng.tychoeclipsebuilder/eclipse-junit-tests/src/main/scripts/library.xml

@@ -66,8 +66,6 @@
 
             test-output   - overrides default output file produced from test run. [May not currently override default?]
 
-            plugin-path   - path to root of plug-in
-
             useEclipseExe - property setting forces test to launch via eclipse executable. [Not fully supported. See bug 387638.]
 
             junit-report-output - output directory for junit reports produced for specified classname.
@@ -150,9 +148,6 @@
         <property
             name="extraVMargs"
             value="" />
-        <property
-            name="plugin-path"
-            value="" />
 
       <property
             name="timeout"
@@ -271,9 +266,6 @@
             <arg value="-junitReportOutput" />
             <arg path="${junit-report-output}" />
             <jvmarg line="${frameworkvmargs} ${loglocation} ${vmargs} ${extraVMargs} ${frameworkperfargs}" />
-            <sysproperty
-                key="PLUGIN_PATH"
-                value="${plugin-path}" />
             <env
                 key="ECLIPSE_I_BUILD_TEST"
                 value="true"/>
@@ -339,7 +331,7 @@
             <arg line="-nosplash" />
             <arg line="--launcher.suppressErrors" />
             <arg line="${consolelog}" />
-            <arg line="-vmargs ${frameworkvmargs} ${loglocation} ${vmargs} ${extraVMargs} -DPLUGIN_PATH=${plugin-path}" />
+            <arg line="-vmargs ${frameworkvmargs} ${loglocation} ${vmargs} ${extraVMargs}" />
         </exec>
         <antcall target="collect-results" />
     </target>

eclipse.platform.releng/bundles/org.eclipse.releng.tests/test.xml

@@ -226,10 +226,6 @@
       <property
         name="classname"
         value="org.eclipse.releng.tests.BuildTests" />
-      <property
-        name="plugin-path"
-        value="${eclipse-home}/plugins/${org.eclipse.releng.tests}" />
-      
       <property
         name="vmargs"
         value="-DdownloadHost=${downloadHost} -DbuildId=${buildId}"  />