Reapply (2x) "[PGO] Fix name encoding for ObjC-like functions"

Function names in ObjC can have spaces in them. This interacts poorly
with name compression, which uses spaces to separate PGO names. Fix the
issue by using a different separator and update a test.

I chose "\01" as the separator because 1) it's non-printable, 2) we
strip it from PGO names, and 3) it's the next natural choice once "\00"
is discarded (that one's overloaded).

What's changed since the original commit?

- I fixed up the covmap-V2 binary format tests using a linux VM.
- I weakened the CHECK lines in instrprof-comdat.h to account for the
  fact that there have been bugfixes to clang coverage. These will be
  fixed up in a follow-up.
- I added an assert to make sure we don't get bitten by this again.
- I constructed the c-general.profraw file without name compression
  enabled to appease some bots.

Differential Revision: http://reviews.llvm.org/D18516

llvm-svn: 264658
diff --git a/llvm/test/tools/llvm-cov/Inputs/instrprof-comdat.h b/llvm/test/tools/llvm-cov/Inputs/instrprof-comdat.h
index e122716..46e73b4 100644
--- a/llvm/test/tools/llvm-cov/Inputs/instrprof-comdat.h
+++ b/llvm/test/tools/llvm-cov/Inputs/instrprof-comdat.h
@@ -13,7 +13,15 @@
     t += I;                               // HEADER: 20| [[@LINE]]|    t += I;
     if (I > ti / 2)                       // HEADER: 20| [[@LINE]]|    if (I > ti 
       t -= 1;                             // HEADER:  8| [[@LINE]]|      t -= 1;
-  }                                       // HEADER: 10| [[@LINE]]|  }
-                                          // HEADER:  1| [[@LINE]]|
-  return t;                               // HEADER:  1| [[@LINE]]|  return t;
+  }                                       // HEADER: {{.*}}| [[@LINE]]|  }
+                                          // HEADER: {{.*}}| [[@LINE]]|
+  return t;                               // HEADER: {{.*}}| [[@LINE]]|  return t;
 }
+
+// FIXME: Some check lines in this function were temporarily weakened to
+// simplify a bugfix.
+
+// To generate the binaries which correspond to this file, you must first
+// compile a program with two calls to Foo<int>::DoIt(10) for each desired
+// architecture. Collect a raw profile from any one of these binaries, index
+// it, and check it in along with the executables.