Subzero: Improve the use of timers.

src/IceBuildDefs.h

Index: src/IceBuildDefs.h
diff --git a/src/IceBuildDefs.h b/src/IceBuildDefs.h
index 948ef13276344b72b7aa05e26ffb635e48fbd6d6..3b32cecab1f6d8b4a4cc00d6243a2bd6f973779b 100644
--- a/src/IceBuildDefs.h
+++ b/src/IceBuildDefs.h
@@ -77,6 +77,8 @@ namespace BuildDefs {
 // The ALLOW_* etc. symbols must be #defined to zero or non-zero.
 /// Return true if ALLOW_DUMP is defined as a non-zero value
 constexpr bool dump() { return ALLOW_DUMP; }
+/// Return true if ALLOW_TIMERS is defined as a non-zero value
+constexpr bool timers() { return ALLOW_TIMERS; }
 /// Return true if ALLOW_LLVM_CL is defined as a non-zero value
 // TODO(stichnot): this ALLOW_LLVM_CL is a TBD option which will
 // allow for replacement of llvm:cl command line processor with a