Temporary remove all -Werror flags

This is needed for transational period of migrating kotlin repository to compiler with version 1.5

(cherry picked from commit 2836a17952dd47b5b8fe176a0b0374c23567b2ff)

kotlin-native/backend.native/build.gradle

@@ -56,7 +56,7 @@ compileCompilerKotlin {
     // but not for Kotlin.
     dependsOn('generateCompilerProto')
     kotlinOptions.jvmTarget = "1.8"
-    kotlinOptions.allWarningsAsErrors=true
+//    kotlinOptions.allWarningsAsErrors=true
     kotlinOptions.freeCompilerArgs += ['-Xopt-in=kotlin.RequiresOptIn', '-Xopt-in=org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI', '-Xskip-prerelease-check']
 }
 
@@ -323,4 +323,4 @@ publishing {
             from components.java
         }
     }
-}
+}