Implement CXCursor support for walking C++ base specifiers.  This includes adding the API hooks clang_isVirtualBase() and clang_getCXXAccessSpecifier() to query properties of the base specifier.

Implements <rdar://problem/8274883>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@112296 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/libclang.exports b/tools/libclang/libclang.exports
index df93a79..60d3352 100644
--- a/tools/libclang/libclang.exports
+++ b/tools/libclang/libclang.exports
@@ -30,6 +30,7 @@
 clang_equalTypes
 clang_formatDiagnostic
 clang_getCString
+clang_getCXXAccessSpecifier
 clang_getCanonicalType
 clang_getClangVersion
 clang_getCompletionAvailability
@@ -95,6 +96,7 @@
 clang_isStatement
 clang_isTranslationUnit
 clang_isUnexposed
+clang_isVirtualBase
 clang_parseTranslationUnit
 clang_reparseTranslationUnit
 clang_saveTranslationUnit