Add ADC (immediate) instruction to ARM integrated assembler.

tests_lit/assembler/arm32/add.ll

 ; Show that we know how to translate add.
 
 ; NOTE: We use -O2 to get rid of memory stores.
 
 ; REQUIRES: allow_dump
 
 ; Compile using standalone assembler.
 ; RUN: %p2i --filetype=asm -i %s --target=arm32 --args -O2 \
 ; RUN:   | FileCheck %s --check-prefix=ASM
 
@@ skipping 53 matching lines @@
 ; IASM-NEXT:  .LAdd2Regs$__0:
 ; IASM-NEXT:    .byte 0x1
 ; IASM-NEXT:    .byte 0x0
 ; IASM-NEXT:    .byte 0x80
 ; IASM-NEXT:    .byte 0xe0
 
 ; IASM-NEXT:    .byte 0x1e
 ; IASM-NEXT:    .byte 0xff
 ; IASM-NEXT:    .byte 0x2f
 ; IASM-NEXT:    .byte 0xe1
+
+define internal i64 @addI64ToR0R1(i64 %p) {
+  %v = add i64 %p, 1
+  ret i64 %v
+}
+
+; ASM-LABEL:addI64ToR0R1:
+; ASM-NEXT:.LaddI64ToR0R1$__0:
+; ASM-NEXT:     adds    r0, r0, #1
+; ASM-NEXT:     adc     r1, r1, #0
+
+; DIS-LABEL:00000020 <addI64ToR0R1>:
+; DIS-NEXT:  20:        e2900001
+; DIS-NEXT:  24:        e2a11000
+
+; IASM-LABEL:addI64ToR0R1:
+; IASM-NEXT:.LaddI64ToR0R1$__0:
+; IASM-NEXT:    .byte 0x1
+; IASM-NEXT:    .byte 0x0
+; IASM-NEXT:    .byte 0x90
+; IASM-NEXT:    .byte 0xe2
+; IASM-NEXT:    .byte 0x0
+; IASM-NEXT:    .byte 0x10
+; IASM-NEXT:    .byte 0xa1
+; IASM-NEXT:    .byte 0xe2