Make TType store a const char * for mangled name.

We would only ever use the c_str value from the mangled name. This
makes it easier to make constexpr TTypes.

Bug: angleproject:1432
Change-Id: I147b3a85f9b8b2453e2d7f4a713d767b22036cc9
Reviewed-on: https://chromium-review.googlesource.com/776277
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
diff --git a/src/compiler/translator/SymbolTable.cpp b/src/compiler/translator/SymbolTable.cpp
index b26acc8..6c38461 100644
--- a/src/compiler/translator/SymbolTable.cpp
+++ b/src/compiler/translator/SymbolTable.cpp
@@ -66,7 +66,7 @@
 
     for (const auto &p : parameters)
     {
-        newName += p.type->getMangledName().c_str();
+        newName += p.type->getMangledName();
     }
     return NewPoolTString(newName.c_str());
 }
@@ -79,7 +79,7 @@
 
     for (TIntermNode *argument : arguments)
     {
-        newName += argument->getAsTyped()->getType().getMangledName().c_str();
+        newName += argument->getAsTyped()->getType().getMangledName();
     }
     return *NewPoolTString(newName.c_str());
 }