Pass ConstString by value (NFC)

My apologies for the large patch. With the exception of ConstString.h
itself it was entirely produced by sed.

ConstString has exactly one const char * data member, so passing a
ConstString by reference is not any more efficient than copying it by
value. In both cases a single pointer is passed. But passing it by
value makes it harder to accidentally return the address of a local
object.

(This fixes rdar://problem/48640859 for the Apple folks)

Differential Revision: https://reviews.llvm.org/D59030

llvm-svn: 355553
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
index 24ca970..5212712 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
@@ -309,7 +309,7 @@
 }
 
 bool ClangExpressionDeclMap::AddPersistentVariable(const NamedDecl *decl,
-                                                   const ConstString &name,
+                                                   ConstString name,
                                                    TypeFromParser parser_type,
                                                    bool is_result,
                                                    bool is_lvalue) {
@@ -424,7 +424,7 @@
 }
 
 bool ClangExpressionDeclMap::AddValueToStruct(const NamedDecl *decl,
-                                              const ConstString &name,
+                                              ConstString name,
                                               llvm::Value *value, size_t size,
                                               lldb::offset_t alignment) {
   assert(m_struct_vars.get());
@@ -604,7 +604,7 @@
 
 addr_t ClangExpressionDeclMap::GetSymbolAddress(Target &target,
                                                 Process *process,
-                                                const ConstString &name,
+                                                ConstString name,
                                                 lldb::SymbolType symbol_type,
                                                 lldb_private::Module *module) {
   SymbolContextList sc_list;
@@ -702,7 +702,7 @@
   return symbol_load_addr;
 }
 
-addr_t ClangExpressionDeclMap::GetSymbolAddress(const ConstString &name,
+addr_t ClangExpressionDeclMap::GetSymbolAddress(ConstString name,
                                                 lldb::SymbolType symbol_type) {
   assert(m_parser_vars.get());
 
@@ -715,7 +715,7 @@
 }
 
 lldb::VariableSP ClangExpressionDeclMap::FindGlobalVariable(
-    Target &target, ModuleSP &module, const ConstString &name,
+    Target &target, ModuleSP &module, ConstString name,
     CompilerDeclContext *namespace_decl, TypeFromUser *type) {
   VariableList vars;