clang: do not add -pie for tsan

Revision 220571 removes the requirement to use -pie for tsan binaries. So remove -pie from driver.
Also s/hasZeroBaseShadow/requiresPIE/ because that is what it is used for. Msan does not have zero-based shadow, but requires pie. And in general the relation between zero-based shadow and pie is unclear.

http://reviews.llvm.org/D6318

llvm-svn: 222526
diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index 17ef107..10079cd 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -2507,7 +2507,7 @@
 }
 
 bool FreeBSD::isPIEDefault() const {
-  return getSanitizerArgs().hasZeroBaseShadow();
+  return getSanitizerArgs().requiresPIE();
 }
 
 /// NetBSD - NetBSD tool chain which can call as(1) and ld(1) directly.
@@ -3383,7 +3383,7 @@
 }
 
 bool Linux::isPIEDefault() const {
-  return getSanitizerArgs().hasZeroBaseShadow();
+  return getSanitizerArgs().requiresPIE();
 }
 
 /// DragonFly - DragonFly tool chain which can call as(1) and ld(1) directly.