runtime: move hash functions to newly created subproject

to reuse in compiler

common/build.gradle

@@ -0,0 +1,16 @@
+import org.jetbrains.kotlin.CompileCppToBitcode
+
+// TODO: consider using some Gradle plugins to build and test
+
+
+task compileHash(type: CompileCppToBitcode) {
+    name 'hash'
+}
+
+task build {
+    dependsOn compileHash
+}
+
+task clean << {
+    delete buildDir
+}

runtime/build.gradle

@@ -7,6 +7,9 @@ task build(type: CompileCppToBitcode) {
     name 'runtime'
     srcRoot file('src/main')
 
+    dependsOn ':common:compileHash'
+    compilerArgs '-I' + project.file('../common/src/hash/headers') // TODO: copy-pasted from 'common'
+    linkerArgs project.file('../common/build/hash.bc').path
 }
 
 task test {

settings.gradle

@@ -4,3 +4,4 @@ include ':Interop:Runtime'
 include ':InteropExample'
 include ':backend.native'
 include ':runtime'
+include ':common'