ScriptConsole: Move from Debugger to QmlJSTools

The console is now a part of qmljstools plugin. The console
appears as an output pane. A dummy QScriptEngine evaluates
expressions when a declarative debug session is not in
progress. During a debug session, the expressions are
evaluated by the debug services.

Task-Number: QTCREATORBUG-7402

Change-Id: Ic2eeac44fb335c706be03b89f8672b0356efe984
Reviewed-by: Christiaan Janssen <christiaan.janssen@digia.com>
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/qmljstools/qmljsinterpreter.cpp

@@ -0,0 +1,58 @@
+#include "qmljsinterpreter.h"
+
+namespace QmlJSTools {
+namespace Internal {
+
+bool QmlJSInterpreter::canEvaluate()
+{
+    int yyaction = 0;
+    int yytoken = -1;
+    int yytos = -1;
+
+    setCode(m_code, 1);
+    m_tokens.append(T_FEED_JS_PROGRAM);
+
+    do {
+        if (++yytos == m_stateStack.size())
+            m_stateStack.resize(m_stateStack.size() * 2);
+
+        m_stateStack[yytos] = yyaction;
+
+again:
+        if (yytoken == -1 && action_index[yyaction] != -TERMINAL_COUNT) {
+            if (m_tokens.isEmpty())
+                yytoken = lex();
+            else
+                yytoken = m_tokens.takeFirst();
+        }
+
+        yyaction = t_action(yyaction, yytoken);
+        if (yyaction > 0) {
+            if (yyaction == ACCEPT_STATE) {
+                --yytos;
+                return true;
+            }
+            yytoken = -1;
+        } else if (yyaction < 0) {
+            const int ruleno = -yyaction - 1;
+            yytos -= rhs[ruleno];
+            yyaction = nt_action(m_stateStack[yytos], lhs[ruleno] - TERMINAL_COUNT);
+        }
+    } while (yyaction);
+
+    const int errorState = m_stateStack[yytos];
+    if (t_action(errorState, T_AUTOMATIC_SEMICOLON) && canInsertAutomaticSemicolon(yytoken)) {
+        yyaction = errorState;
+        m_tokens.prepend(yytoken);
+        yytoken = T_SEMICOLON;
+        goto again;
+    }
+
+    if (yytoken != EOF_SYMBOL)
+        return true;
+
+    return false;
+}
+
+} // namespace Internal
+} // namespace QmlJSTools