[profile] use GetComputerNameExW instead of gethostname on Windows

Summary: In profile data paths, we replace "%h" with the hostname of the machine the program is running on. On Windows, we used gethostname() to obtain the hostname. This requires linking with ws2_32. With this change, we instead get the hostname from GetComputerNameExW(), which does not require ws2_32.

Reviewers: rnk, vsk, amccarth

Subscribers: zturner, ruiu, hans

Differential Revision: https://reviews.llvm.org/D27178

llvm-svn: 288146
diff --git a/compiler-rt/lib/profile/InstrProfilingFile.c b/compiler-rt/lib/profile/InstrProfilingFile.c
index 44f5d9a..f82080c 100644
--- a/compiler-rt/lib/profile/InstrProfilingFile.c
+++ b/compiler-rt/lib/profile/InstrProfilingFile.c
@@ -300,18 +300,18 @@
       if (FilenamePat[++I] == 'p') {
         if (!NumPids++) {
           if (snprintf(PidChars, MAX_PID_SIZE, "%d", getpid()) <= 0) {
-            PROF_WARN(
-                "Unable to parse filename pattern %s. Using the default name.",
-                FilenamePat);
+            PROF_WARN("Unable to get pid for filename pattern %s. Using the "
+                      "default name.",
+                      FilenamePat);
             return -1;
           }
         }
       } else if (FilenamePat[I] == 'h') {
         if (!NumHosts++)
           if (COMPILER_RT_GETHOSTNAME(Hostname, COMPILER_RT_MAX_HOSTLEN)) {
-            PROF_WARN(
-                "Unable to parse filename pattern %s. Using the default name.",
-                FilenamePat);
+            PROF_WARN("Unable to get hostname for filename pattern %s. Using "
+                      "the default name.",
+                      FilenamePat);
             return -1;
           }
       } else if (containsMergeSpecifier(FilenamePat, I)) {