[BOLT][NFC] Remove redundant dependent template type

Summary:
Reduce code size by removing redundant dependent template type
from RewriteInstance methods.

Code size savings (via bloaty on llvm-bolt Debug build):
```
symbol,vmsize,filesize -> vmsize,filesize (delta vmsize,filesize)
updateELFSymbolTable         57096,59600 -> 56656,59048 (440,552)
updateELFSymbolTable::lambda 35957,55277 -> 35949,54485   (8,792)
getOutputSections            20592,21440 -> 20372,21156 (220,284)
getOutputSections::lambda      1792,5300 ->   1792,5372   (0,-72)

total delta (668,1556)
```

Reviewed By: maksfb

FBD33589393

bolt/include/bolt/Rewrite/RewriteInstance.h

@@ -279,9 +279,8 @@ class RewriteInstance {
 
   /// Return a list of all sections to include in the output binary.
   /// Populate \p NewSectionIndex with a map of input to output indices.
-  template <typename ELFT,
-            typename ELFShdrTy = typename object::ELFObjectFile<ELFT>::Elf_Shdr>
-  std::vector<ELFShdrTy>
+  template <typename ELFT>
+  std::vector<typename object::ELFObjectFile<ELFT>::Elf_Shdr>
   getOutputSections(object::ELFObjectFile<ELFT> *File,
                     std::vector<uint32_t> &NewSectionIndex);
 
@@ -293,13 +292,12 @@ class RewriteInstance {
   /// based on the input file symbol table passed in \p SymTabSection.
   /// \p IsDynSym is set to true for dynamic symbol table since we
   /// are updating it in-place with minimal modifications.
-  template <typename ELFT,
-            typename ELFShdrTy = typename object::ELFObjectFile<ELFT>::Elf_Shdr,
-            typename WriteFuncTy, typename StrTabFuncTy>
-  void updateELFSymbolTable(object::ELFObjectFile<ELFT> *File, bool IsDynSym,
-                            const ELFShdrTy &SymTabSection,
-                            const std::vector<uint32_t> &NewSectionIndex,
-                            WriteFuncTy Write, StrTabFuncTy AddToStrTab);
+  template <typename ELFT, typename WriteFuncTy, typename StrTabFuncTy>
+  void updateELFSymbolTable(
+      object::ELFObjectFile<ELFT> *File, bool IsDynSym,
+      const typename object::ELFObjectFile<ELFT>::Elf_Shdr &SymTabSection,
+      const std::vector<uint32_t> &NewSectionIndex, WriteFuncTy Write,
+      StrTabFuncTy AddToStrTab);
 
   /// Add a notes section containing the BOLT revision and command line options.
   void addBoltInfoSection();

bolt/lib/Rewrite/RewriteInstance.cpp

@@ -4019,10 +4019,11 @@ bool RewriteInstance::shouldStrip(const ELFShdrTy &Section,
   return false;
 }
 
-template <typename ELFT, typename ELFShdrTy>
-std::vector<ELFShdrTy>
+template <typename ELFT>
+std::vector<typename object::ELFObjectFile<ELFT>::Elf_Shdr>
 RewriteInstance::getOutputSections(ELFObjectFile<ELFT> *File,
                                    std::vector<uint32_t> &NewSectionIndex) {
+  using ELFShdrTy = typename ELFObjectFile<ELFT>::Elf_Shdr;
   const ELFFile<ELFT> &Obj = File->getELFFile();
   typename ELFT::ShdrRange Sections = cantFail(Obj.sections());
 
@@ -4255,14 +4256,11 @@ void RewriteInstance::patchELFSectionHeaderTable(ELFObjectFile<ELFT> *File) {
   OS.pwrite(reinterpret_cast<const char *>(&NewEhdr), sizeof(NewEhdr), 0);
 }
 
-template <typename ELFT, typename ELFShdrTy, typename WriteFuncTy,
-          typename StrTabFuncTy>
+template <typename ELFT, typename WriteFuncTy, typename StrTabFuncTy>
 void RewriteInstance::updateELFSymbolTable(
-    ELFObjectFile<ELFT> *File,
-    bool IsDynSym,
-    const ELFShdrTy &SymTabSection,
-    const std::vector<uint32_t> &NewSectionIndex,
-    WriteFuncTy Write,
+    ELFObjectFile<ELFT> *File, bool IsDynSym,
+    const typename object::ELFObjectFile<ELFT>::Elf_Shdr &SymTabSection,
+    const std::vector<uint32_t> &NewSectionIndex, WriteFuncTy Write,
     StrTabFuncTy AddToStrTab) {
   const ELFFile<ELFT> &Obj = File->getELFFile();
   using ELFSymTy = typename ELFObjectFile<ELFT>::Elf_Sym;