libdecnumber: Introduce decNumberIntegralToInt64

Introduce a new conversion function to the libdecnumber library.
This function converts a decNumber to a signed 64-bit integer.
In order to support 64-bit integers (which may have up to 19
decimal digits), the existing "powers of 10" array is expanded
from 10 to 19 entries.

Signed-off-by: Tom Musta <tommusta@gmail.com>
[agraf: fix 32bit host compile]
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/libdecnumber/decContext.c b/libdecnumber/decContext.c
index 6847106..8b6ae21 100644
--- a/libdecnumber/decContext.c
+++ b/libdecnumber/decContext.c
@@ -56,8 +56,10 @@
 /* ------------------------------------------------------------------ */
 /* Powers of ten (powers[n]==10**n, 0<=n<=9)			      */
 /* ------------------------------------------------------------------ */
-const uInt DECPOWERS[10]={1, 10, 100, 1000, 10000, 100000, 1000000,
-			  10000000, 100000000, 1000000000};
+const uLong DECPOWERS[19] = {1, 10, 100, 1000, 10000, 100000, 1000000,
+  10000000, 100000000, 1000000000, 10000000000ULL, 100000000000ULL,
+  1000000000000ULL, 10000000000000ULL, 100000000000000ULL, 1000000000000000ULL,
+  10000000000000000ULL, 100000000000000000ULL, 1000000000000000000ULL, };
 
 /* ------------------------------------------------------------------ */
 /* decContextClearStatus -- clear bits in current status	      */