Add mul instruction to ARM integrated assembler.

tests_lit/assembler/arm32/mul.ll

+; Show that we know how to translate mul.
+
+; 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
+
+; Show bytes in assembled standalone code.
+; RUN: %p2i --filetype=asm -i %s --target=arm32 --assemble --disassemble \
+; RUN:   --args -O2 | FileCheck %s --check-prefix=DIS
+
+; Compile using integrated assembler.
+; RUN: %p2i --filetype=iasm -i %s --target=arm32 --args -O2 \
+; RUN:   | FileCheck %s --check-prefix=IASM
+
+; Show bytes in assembled integrated code.
+; RUN: %p2i --filetype=iasm -i %s --target=arm32 --assemble --disassemble \
+; RUN:   --args -O2 | FileCheck %s --check-prefix=DIS
+
+define internal i32 @MulTwoRegs(i32 %a, i32 %b) {
+  %v = mul i32 %a, %b
+  ret i32 %v
+}
+
+; ASM-LABEL:MulTwoRegs:
+; ASM-NEXT:.LMulTwoRegs$__0:
+; ASM-NEXT:     mul     r0, r0, r1
+
+; DIS-LABEL:00000000 <MulTwoRegs>:
+; DIS-NEXT:   0:        e0000190
+
+; IASM-LABEL:MulTwoRegs:
+; IASM-NEXT:.LMulTwoRegs$__0:
+; IASM-NEXT:    .byte 0x90
+; IASM-NEXT:    .byte 0x1
+; IASM-NEXT:    .byte 0x0
+; IASM-NEXT:    .byte 0xe0
+
+define internal i64 @MulTwoI64Regs(i64 %a, i64 %b) {
+  %v = mul i64 %a, %b
+  ret i64 %v
+}
+
+; ASM-LABEL:MulTwoI64Regs:
+; ASM-NEXT:.LMulTwoI64Regs$__0:
+; ASM-NEXT:     mul     r3, r0, r3
+; ASM-NEXT:     mla     r1, r2, r1, r3
+; ASM-NEXT:     umull   r0, r2, r0, r2
+; ASM:          add     r2, r2, r1
+; ASM-NEXT:     mov     r1, r2
+; ASM:          bx      lr
+
+
+; DIS-LABEL:00000010 <MulTwoI64Regs>:
+; DIS-NEXT:  10:        e0030390
+; DIS-NEXT:  14:        e0213192
+; DIS-NEXT:  18:        e0820290
+; DIS-NEXT:  1c:        e0822001
+; DIS-NEXT:  20:        e1a01002
+; DIS-NEXT:  24:        e12fff1e
+
+; IASM-LABEL:MulTwoI64Regs:
+; IASM-NEXT:.LMulTwoI64Regs$__0:
+; IASM-NEXT:    .byte 0x90
+; IASM-NEXT:    .byte 0x3
+; IASM-NEXT:    .byte 0x3
+; IASM-NEXT:    .byte 0xe0
+; IASM-NEXT:    mla     r1, r2, r1, r3
+; IASM-NEXT:    umull   r0, r2, r0, r2
+; IASM-NEXT:    .byte 0x1
+; IASM-NEXT:    .byte 0x20
+; IASM-NEXT:    .byte 0x82
+; IASM-NEXT:    .byte 0xe0
+; IASM-NEXT:    mov     r1, r2
+; IASM-NEXT:    .byte 0x1e
+; IASM-NEXT:    .byte 0xff
+; IASM-NEXT:    .byte 0x2f
+; IASM-NEXT:    .byte 0xe1