[libclc] [libclc][NFC] Fix build warning typedef-redefinition (PR #177888)

[Matt Arsenault via cfe-commits]

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@@ -9,6 +9,8 @@
 #ifndef __CLC_CLCTYPES_H_
 #define __CLC_CLCTYPES_H_
 
+#ifndef _OPENCL_BASE_H_
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arsenm wrote:

Just delete this header? Libclc has no need to redefined any of this stuff.

https://github.com/llvm/llvm-project/pull/177888