[PATCH] Fix hardcoded path seperator in two code locations

[Reid Kleckner]

================
Comment at: lib/Support/Path.cpp:573
@@ +572,3 @@
+static const char preferred_separator_string[] = { preferred_separator, '\0' };
+static const StringRef preferred_separator_StringRef(preferred_separator_string);
+
----------------
We don't need this global data.  It will probably require a dynamic initializer, which is lame.  Clang is smart enough to optimize out strlen if you just return preferred_separator directly:

  $ cat t.cpp
  extern "C" int strlen(const char *s);
  struct StringRef {
    const char *p;
    size_t len;
    StringRef(const char *s) : p(s), len(strlen(s)) {}
  };
  static const char preferred_sep[] = { '/', '\0' };
  StringRef getPrefSep() {
    return StringRef(preferred_sep);
  }
  
  $ clang -c t.cpp -O2 -S -o - --target=x86_64-linux -fPIC | grep '^\s[^\.]'
          leaq    _ZL13preferred_sep(%rip), %rax
          movl    $1, %edx
          retq

http://reviews.llvm.org/D3687