build: add "LD_LIBRARY_PATH=llvmDir/lib" for Linux

InteropExample/build.gradle

@@ -31,3 +31,7 @@ dependencies {
 }
 
 mainClassName = 'MainKt'
+
+run {
+    environment 'LD_LIBRARY_PATH' : "$llvmDir/lib"
+}

backend.native/build.gradle

@@ -86,6 +86,8 @@ task run(type: JavaExec) {
    doFirst {
        args '-runtime', project(':runtime').build.outputs.files.singleFile
    }
+
+   environment 'LD_LIBRARY_PATH' : "$llvmDir/lib"
 }