[libclc] [libclc][CMake] Test compiler for all build targets (PR #185376)

[Joseph Huber via cfe-commits]

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@@ -114,6 +112,14 @@ else()
   endforeach()
 endif()
 
+if( NOT LIBCLC_TARGETS_TO_BUILD )
+  message( FATAL_ERROR
+    "LIBCLC_TARGETS_TO_BUILD is empty. Specify at least one target or use 'all'.\n"
+    "Valid targets are: ${LIBCLC_TARGETS_ALL}\n")
+endif()
+
+enable_language( CLC )
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jhuber6 wrote:

Checking for language support shouldn't depend on the targets, we could maybe have a separate check that verifies the passed-in triple is valid.

https://github.com/llvm/llvm-project/pull/185376