Simplify Boolean expressions

This patch simplifies boolean expressions acorss LLDB. It was generated
using clang-tidy with the following command:

run-clang-tidy.py -checks='-*,readability-simplify-boolean-expr' -format -fix $PWD

Differential revision: https://reviews.llvm.org/D55584

llvm-svn: 349215
diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index 310eb79..a6249b3 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -1839,7 +1839,7 @@
           error_ptr->SetErrorString(
               "Expression stack needs at least 1 item for DW_OP_abs.");
         return false;
-      } else if (stack.back().ResolveValue(exe_ctx).AbsoluteValue() == false) {
+      } else if (!stack.back().ResolveValue(exe_ctx).AbsoluteValue()) {
         if (error_ptr)
           error_ptr->SetErrorString(
               "Failed to take the absolute value of the first stack item.");
@@ -1972,7 +1972,7 @@
               "Expression stack needs at least 1 item for DW_OP_neg.");
         return false;
       } else {
-        if (stack.back().ResolveValue(exe_ctx).UnaryNegate() == false) {
+        if (!stack.back().ResolveValue(exe_ctx).UnaryNegate()) {
           if (error_ptr)
             error_ptr->SetErrorString("Unary negate failed.");
           return false;
@@ -1993,7 +1993,7 @@
               "Expression stack needs at least 1 item for DW_OP_not.");
         return false;
       } else {
-        if (stack.back().ResolveValue(exe_ctx).OnesComplement() == false) {
+        if (!stack.back().ResolveValue(exe_ctx).OnesComplement()) {
           if (error_ptr)
             error_ptr->SetErrorString("Logical NOT failed.");
           return false;
@@ -2100,8 +2100,8 @@
       } else {
         tmp = stack.back();
         stack.pop_back();
-        if (stack.back().ResolveValue(exe_ctx).ShiftRightLogical(
-                tmp.ResolveValue(exe_ctx)) == false) {
+        if (!stack.back().ResolveValue(exe_ctx).ShiftRightLogical(
+                tmp.ResolveValue(exe_ctx))) {
           if (error_ptr)
             error_ptr->SetErrorString("DW_OP_shr failed.");
           return false;