Drop hard check on proprietary compiler

SDCLANG_PATH is required for the use of proprietary compiler.
Since support for proprietary compilers are dropped, drop the
hard check on this.

Issue: FP3-A11#181
Change-Id: I72d8a7ff32e0f7a1fd45ae08bd200fb0404e9919
diff --git a/cc/config/global.go b/cc/config/global.go
index b633a72..8d4b26e 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -374,11 +374,6 @@
 		}
 	}
 
-	// Sanity check SDCLANG_PATH
-	if envPath := android.SdclangEnv["SDCLANG_PATH"]; sdclangPath == "" && envPath == "" {
-		panic("SDCLANG_PATH can not be empty")
-	}
-
 	// Override SDCLANG_PATH if the variable is set in the environment
 	pctx.VariableFunc("SDClangBin", func(ctx android.PackageVarContext) string {
 		if override := ctx.Config().Getenv("SDCLANG_PATH"); override != "" {