[codegen][debug] make runtime debug information friendly to generated one.

- inroduced function generation context containing mostly functionality local to function generation
- initial debug location is linked with basic block.
- then on each expression location is tuned.
- removed manual placement of debug location dictations over the place.

- refactoring removed unused declarations

runtime/build.gradle

@@ -26,6 +26,7 @@ targetList.each { targetName ->
         dependsOn "${targetName}Launcher"
         target targetName
         compilerArgs targetArgs[targetName]
+        compilerArgs '-g'
         compilerArgs '-I' + project.file('../common/src/hash/headers')
         compilerArgs '-I' + project.file(rootProject.ext.get("${targetName}LibffiDir") + "/include")
         linkerArgs project.file("../common/build/$targetName/hash.bc").path
@@ -38,6 +39,7 @@ targetList.each { targetName ->
         srcRoot file('src/launcher')
         target targetName
         compilerArgs targetArgs[targetName]
+        compilerArgs '-g'
         compilerArgs '-I' + project.file('../common/src/hash/headers')
         compilerArgs '-I' + project.file('src/main/cpp')
     }