[compiler-rt] Apply modernize-use-nullptr fixes in sanitizers

- Trim spaces.
- Use nullptr in place of 0 for pointer variables.
- Use '!p' in place of 'p == 0' for null pointer checks.
- Add blank lines to separate function definitions.
- Add 'extern "C"' or 'namespace foo' comments after the appropriate
  closing brackets

This is a continuation of work from 409b7b82. The focus here is on the
various sanitizers (not sanitizer_common, as before).

Patch by Eugene Zelenko!

Differential Revision: http://reviews.llvm.org/D13225

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@248966 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/msan/msan_thread.h b/lib/msan/msan_thread.h
index bc605b89a..ed22e67ed 100644
--- a/lib/msan/msan_thread.h
+++ b/lib/msan/msan_thread.h
@@ -32,7 +32,7 @@ class MsanThread {
   uptr stack_bottom() { return stack_bottom_; }
   uptr tls_begin() { return tls_begin_; }
   uptr tls_end() { return tls_end_; }
-  bool IsMainThread() { return start_routine_ == 0; }
+  bool IsMainThread() { return start_routine_ == nullptr; }
 
   bool AddrIsInStack(uptr addr) {
     return addr >= stack_bottom_ && addr < stack_top_;