Merge pull request #9050 from JinShil/fix_19014

Fix Issue 19014 - Compiler imports symbols that aren't actually imported
merged-on-behalf-of: Nicholas Wilson <thewilsonator@users.noreply.github.com>

Author: dlang-bot

test/compilable/test19014.d

@@ -0,0 +1,12 @@
+// https://issues.dlang.org/show_bug.cgi?id=19014
+
+import core.stdc.config;
+
+void main()
+{
+    if (true)
+    {
+    	static import core.stdc.math;
+    }
+    static assert(!__traits(compiles, core.stdc.math.cos(0))); 
+}