[Courgette] Simplify EncodedProgram Label addition code; removed "1.01 x" memory fix.

This CL simplifies how Labels get flattened to a list of RVAs. In the past
EncodedProgram used DefineAbs32Label() / DefineRel32Label(), which let callers
add one Label at a time. Complexity arose from:
- Function pointer usage to avoid duplicate code for abs32 and rel32.
- Need for EncodedProgram to dynamically adjust size of RVA list. This led to
  inefficient array resizing, which was fixed by the "1.01 x" memory growth.

Change: We now pass the collection of abs32 and rel32 Labels to EncodedProgram.
This simplifies the interface, and allows EncodedProgram to find the max indexes
and preallocated buffers. The trade-off is increased test code complexity, since
we'd need to create Label collection.

Other changes:
- Update namespace{} for EncodedProgram and its tests.
- Add more Label constructors (for testing).
- Add LabelManager::GetIndexBound(), for LabelVector and RVAToLabel.
- Add kUnassignedRVA in image_utils.h, with checks for its absence in images.

Review URL: https://codereview.chromium.org/1571913003

Cr-Commit-Position: refs/heads/master@{#370200}

1 files changed, 5 insertions, 1 deletions

diff --git a/courgette/image_utils.h b/courgette/image_utils.h
index 9a077fd..f958cc1 100644
--- a/courgette/image_utils.h
+++ b/courgette/image_utils.h
@@ -15,6 +15,7 @@
 namespace courgette {
 
 typedef uint32_t RVA;
+const RVA kUnassignedRVA = 0xFFFFFFFFU;
 
 // A Label is a symbolic reference to an address.  Unlike a conventional
 // assembly language, we always know the address.  The address will later be
@@ -25,13 +26,16 @@ class Label {
  public:
   enum : int { kNoIndex = -1 };
   explicit Label(RVA rva) : rva_(rva) {}
+  Label(RVA rva, int index) : rva_(rva), index_(index) {}
+  Label(RVA rva, int index, int32_t count)
+      : rva_(rva), index_(index), count_(count) {}
 
   bool operator==(const Label& other) const {
     return rva_ == other.rva_ && index_ == other.index_ &&
            count_ == other.count_;
   }
 
-  RVA rva_ = 0;           // Address referred to by the label.
+  RVA rva_ = kUnassignedRVA;  // Address referred to by the label.
   int index_ = kNoIndex;  // Index of address in address table.
   int32_t count_ = 0;
 };