Simple HPHP Changes for HPHP with Clang

Simple HPHP Changes for HPHP with Clang

Some simple changes for HPHP to help make it clang friendly

---hphp/compiler/package.cpp
---hphp/compiler/package.h
---hphp/runtime/ext/ext_curl.cpp
---hphp/runtime/ext/pdo_mysql.cpp
---hphp/tools/tc-print/offline-x86-code.h
---hphp/util/async_func.cpp
---hphp/util/async_func.h
---hphp/util/compression.cpp
---hphp/util/compression.h
---hphp/util/db_conn.cpp
---hphp/util/db_conn.h
  Deleted unused private fields

~~~hphp/compiler/analysis/symbol_table.h
  Static assert had to be outside the union

+++hphp/runtime/TARGETS
  Added clang specific flag to supress unneded declaration warning

~~~hphp/runtime/base/datatype.h
  Use of logical '&&' with constant operand. Added !=0 to remove warning,

~~~hphp/runtime/base/string_data.h
  Static fields cannot be declared in an anonymous struct/union

~~~hphp/runtime/ext/bcmath/TARGETS
  Moved gcc specific flag from preprocessor_flags to compiler_specific_flags

~---hphp/runtime/ext/pdo_mysql.cpp
  Removed unnecessary self asignment for row_count

~~~hphp/runtime/vm/bytecode.h
  Added default return statement

~---hphp/runtime/vm/jit/codegen.cpp
  spillSlotsToSize was unused

~~~hphp/runtime/vm/jit/irtranslator.cpp
~~~hphp/runtime/vm/jit/linearscan.cpp
  The c++ standard states default arguments shall not be specified in the
  parameter-declaration-clause of a lambda-declarator.

~~~hphp/runtime/vm/jit/vectortranslator-internal.h
  Clang had some issues determining the correct cast when these macros were used
  A simple '!= 0' check was added to make things explicit for clang.

~~~hphp/tools/tc-print/perf-events.h
  Added parens to make clang happy

+++hphp/util/asm-x64.h
  The constexpr needed to be initialized

+++hphp/util/base.h
  Clang also supports tr1 libraries

~~~hphp/util/bits.h
  Again, clang had issues with implicit casting to bool.
  added != 0 check

~~~hphp/util/malloc_size_class.h
  Ambiguous operator precedence. Added parentheses.

~~~hphp/util/thread_local.h
  Misspelled function