clang-format: Add an option 'SpaceAfterCStyleCast'.

This permits to add a space after closing parenthesis of a C-style cast.
Defaults to false to preserve old behavior.

Fixes llvm.org/PR19982.

Before:
  (int)i;

After:
  (int) i;

Patch by Marek Kurdej.

llvm-svn: 217022
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 451e834..6f00acf 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -7721,6 +7721,38 @@
                "default:\n"
                "  break;\n"
                "}", Spaces);
+
+  Spaces.SpaceAfterCStyleCast = true;
+  verifyFormat("call(x, y, z);", Spaces);
+  verifyFormat("while (( bool ) 1)\n"
+               "  continue;",
+               Spaces);
+  verifyFormat("for (;;)\n"
+               "  continue;",
+               Spaces);
+  verifyFormat("if (true)\n"
+               "  f( );\n"
+               "else if (true)\n"
+               "  f( );",
+               Spaces);
+  verifyFormat("do {\n"
+               "  do_something(( int ) i);\n"
+               "} while (something( ));",
+               Spaces);
+  verifyFormat("switch (x) {\n"
+               "default:\n"
+               "  break;\n"
+               "}",
+               Spaces);
+  Spaces.SpacesInCStyleCastParentheses = false;
+  Spaces.SpaceAfterCStyleCast = true;
+  verifyFormat("while ((bool) 1)\n"
+               "  continue;",
+               Spaces);
+  verifyFormat("do {\n"
+               "  do_something((int) i);\n"
+               "} while (something( ));",
+               Spaces);
 }
 
 TEST_F(FormatTest, ConfigurableSpacesInSquareBrackets) {
@@ -8306,6 +8338,7 @@
   CHECK_PARSE_BOOL(SpaceInEmptyParentheses);
   CHECK_PARSE_BOOL(SpacesInContainerLiterals);
   CHECK_PARSE_BOOL(SpacesInCStyleCastParentheses);
+  CHECK_PARSE_BOOL(SpaceAfterCStyleCast);
   CHECK_PARSE_BOOL(SpaceBeforeAssignmentOperators);
 }