-Wempty-body: fix false negative triggered by macros

When if statement condition ended in a macro:

    if (ptr == NULL);

the check used to consider the definition location of NULL, instead of the
current line.

Patch by Manasij Mukherjee.

llvm-svn: 232295

clang/lib/Sema/SemaChecking.cpp

@@ -8625,7 +8625,7 @@ bool ShouldDiagnoseEmptyStmtBody(const SourceManager &SourceMgr,
 
   // Get line numbers of statement and body.
   bool StmtLineInvalid;
-  unsigned StmtLine = SourceMgr.getSpellingLineNumber(StmtLoc,
+  unsigned StmtLine = SourceMgr.getPresumedLineNumber(StmtLoc,
                                                       &StmtLineInvalid);
   if (StmtLineInvalid)
     return false;