Switch from 'patch' to 'git apply' because CentOS 6's 'patch' doesn't support renaming files.

PiperOrigin-RevId: 253951856

third_party/icu/udata.patch

@@ -1,5 +1,5 @@
---- /icu4c/source/common/unicode/uconfig.h	2018-06-19 22:34:56.000000000 -0700
-+++ /ice4c/source/common/unicode/uconfig.h.new	2019-03-12 10:12:35.896095657 -0700
+--- a/icu4c/source/common/unicode/uconfig.h
++++ b/icu4c/source/common/unicode/uconfig.h
 @@ -55,6 +55,11 @@
  #include "uconfig_local.h"
  #endif
@@ -13,8 +13,8 @@
   * \def U_DEBUG
   * Determines whether to include debugging code.
 
---- /icu4c/source/common/udata.cpp.old	2018-06-19 22:34:56.000000000 -0700
-+++ /icu4c/source/common/udata.cpp	2018-10-19 14:26:09.778950855 -0700
+--- a/icu4c/source/common/udata.cpp
++++ b/icu4c/source/common/udata.cpp
 @@ -18,15 +18,15 @@
  
  #include "unicode/utypes.h"  /* U_PLATFORM etc. */

third_party/repo.bzl

@@ -61,14 +61,11 @@ def _repos_are_siblings():
     return Label("@foo//bar").workspace_root.startswith("../")
 
 # Apply a patch_file to the repository root directory
-# Runs 'patch -p1'
+# Runs 'git apply'
 def _apply_patch(ctx, patch_file):
-    # Don't check patch on Windows, because patch is only available under bash.
-    if not _is_windows(ctx) and not ctx.which("patch"):
-        fail("patch command is not found, please install it")
     cmd = _wrap_bash_cmd(
         ctx,
-        ["patch", "-p1", "-d", ctx.path("."), "-i", ctx.path(patch_file)],
+        ["git", "apply", "-v", ctx.path(patch_file)],
     )
     _execute_and_check_ret_code(ctx, cmd)