[Frontend][C++] Add translation for static cast

Summary:
@public
Translate CXXStaticCastExpr

Test Plan:
Add test, confirm that it gets translated.
Also create example to see that infer reports null dereference with this change:
  struct X { int a; };
  int main() {
    X *x = static_cast<X*>(nullptr); // <- reports now
    //X *x = (X*)nullptr; // <- reported before
    return x->a;
  }

infer/src/clang/cTrans.ml

@@ -1701,7 +1701,8 @@ struct
     | ObjCBridgedCastExpr(stmt_info, stmt_list, expr_info, cast_kind, _) ->
         cast_exprs_trans trans_state stmt_info stmt_list expr_info cast_kind true
     | ImplicitCastExpr(stmt_info, stmt_list, expr_info, cast_kind)
-    | CStyleCastExpr(stmt_info, stmt_list, expr_info, cast_kind, _) ->
+    | CStyleCastExpr(stmt_info, stmt_list, expr_info, cast_kind, _)
+    | CXXStaticCastExpr(stmt_info, stmt_list, expr_info, cast_kind, _, _) ->
         cast_exprs_trans trans_state stmt_info stmt_list expr_info cast_kind false
 
     | IntegerLiteral(stmt_info, _, expr_info, integer_literal_info) ->

infer/tests/codetoanalyze/cpp/frontend/types/casts.cpp

@@ -0,0 +1,4 @@
+void stat_cast() {
+  int a;
+  long long la = static_cast<long long>(a);
+}

infer/tests/codetoanalyze/cpp/frontend/types/casts.dot

@@ -0,0 +1,13 @@
+digraph iCFG {
+3 [label="3:  DeclStmt \n   n$0=*&a:int  [line 3]\n  *&la:long long =n$0 [line 3]\n  REMOVE_TEMPS(n$0); [line 3]\n  NULLIFY(&a,false); [line 3]\n  NULLIFY(&la,false); [line 3]\n  APPLY_ABSTRACTION; [line 3]\n " shape="box"]
+	
+
+	 3 -> 2 ;
+2 [label="2: Exit stat_cast \n  " color=yellow style=filled]
+	
+
+1 [label="1: Start stat_cast\nFormals: \nLocals:  a:int  la:long long  \n   DECLARE_LOCALS(&return,&a,&la); [line 1]\n  NULLIFY(&la,false); [line 1]\n " color=yellow style=filled]
+	
+
+	 1 -> 3 ;
+}

infer/tests/frontend/cpp/CastsTest.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2013- Facebook.
+ * All rights reserved.
+ */
+
+package frontend.cpp;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static utils.matchers.DotFilesEqual.dotFileEqualTo;
+
+import com.google.common.collect.ImmutableList;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+
+import utils.DebuggableTemporaryFolder;
+import utils.InferException;
+import utils.InferRunner;
+
+public class CastsTest {
+
+  @Rule
+  public DebuggableTemporaryFolder folder = new DebuggableTemporaryFolder();
+
+  @Test
+  public void whenCaptureRunCommaThenDotFilesAreTheSame()
+      throws InterruptedException, IOException, InferException {
+    String literal_src =
+        "infer/tests/codetoanalyze/cpp/frontend/types/casts.cpp";
+
+    String literal_dotty =
+        "infer/tests/codetoanalyze/cpp/frontend/types/casts.dot";
+
+    ImmutableList<String> inferCmd =
+        InferRunner.createCPPInferCommandFrontend(
+            folder,
+            literal_src);
+    File newDotFile = InferRunner.runInferFrontend(inferCmd);
+    assertThat(
+        "In the capture of " + literal_src +
+            " the dotty files should be the same.",
+        newDotFile, dotFileEqualTo(literal_dotty));
+  }
+}