Add --enable-llvmc-dynamic configure option.

Controls whether libCompilerDriver should be loaded dynamically. By default this
is needed only on Win32, to make dynamic plugins work.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74759 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Makefile.config.in b/Makefile.config.in
index 44d7416..e715902 100644
--- a/Makefile.config.in
+++ b/Makefile.config.in
@@ -297,3 +297,9 @@
 
 # Location of the plugin header file for gold.
 BINUTILS_INCDIR := @BINUTILS_INCDIR@
+
+# When ENABLE_LLVMC_DYNAMIC is enabled, LLVMC will link libCompilerDriver
+# dynamically. This is needed to make dynamic plugins work on some targets
+# (Windows).
+ENABLE_LLVMC_DYNAMIC = 0
+#@ENABLE_LLVMC_DYNAMIC@