Export runTcInteractive from TcRnDriver, and from GHC (Trac #8878)

(cherry picked from commit 60bbc0af)

compiler/main/GHC.hs

@@ -102,6 +102,7 @@ module GHC (
         parseName,
         RunResult(..),  
         runStmt, runStmtWithLocation, runDecls, runDeclsWithLocation,
+        runTcInteractive,   -- Desired by some clients (Trac #8878)
         parseImportDecl, SingleStep(..),
         resume,
         Resume(resumeStmt, resumeThreadId, resumeBreakInfo, resumeSpan,
@@ -257,6 +258,7 @@ module GHC (
 import ByteCodeInstr
 import BreakArray
 import InteractiveEval
+import TcRnDriver       ( runTcInteractive )
 #endif
 
 import HscMain

compiler/typecheck/TcRnDriver.lhs

@@ -13,6 +13,7 @@ module TcRnDriver (
         getModuleInterface,
         tcRnDeclsi,
         isGHCiMonad,
+        runTcInteractive,    -- Used by GHC API clients (Trac #8878)
 #endif
         tcRnLookupName,
         tcRnGetInfo,