Roll V8 back to 3.6

Roll back to V8 3.6 to fix x86 build, we don't have ucontext.h.

This reverts commits:
5d4cdbf7a67d3662fa0bee4efdb7edd8daec9b0b
c7cc028aaeedbbfa11c11d0b7b243b3d9e837ed9
592a9fc1d8ea420377a2e7efd0600e20b058be2b

Bug: 5688872
Change-Id: Ic961bb5e65b778e98bbfb71cce71d99fa949e995
diff --git a/src/version.cc b/src/version.cc
index d23fe61..2c21152 100644
--- a/src/version.cc
+++ b/src/version.cc
@@ -33,9 +33,9 @@
 // NOTE these macros are used by the SCons build script so their names
 // cannot be changed without changing the SCons build script.
 #define MAJOR_VERSION     3
-#define MINOR_VERSION     9
-#define BUILD_NUMBER      24
-#define PATCH_LEVEL       9
+#define MINOR_VERSION     6
+#define BUILD_NUMBER      6
+#define PATCH_LEVEL       19
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)
 #define IS_CANDIDATE_VERSION 0