Standardize indentation using spaces.

Most files already used spaces, but three used tabs for indentation. These have been converted to use spaces. This allows the files to be displayed with proper formatting in modern editors and on GitHub. It also removes any dependency on SysTabs settings when assembling them.

The spacing in fpextra.asm was also modified to use standard column positions.

There are no non-whitespace changes in this commit.

fpextra.asm

@@ -26,8 +26,8 @@ fpextra  private                        dummy segment
 ~SinglePrecision start
          tsc
          clc
-         adc     #4
-         ldy     #0
+         adc   #4
+         ldy   #0
          phy
          pha
          phy
@@ -53,8 +53,8 @@ fpextra  private                        dummy segment
 ~DoublePrecision start
          tsc
          clc
-         adc     #4
-         ldy     #0
+         adc   #4
+         ldy   #0
          phy
          pha
          phy
@@ -83,19 +83,19 @@ fpextra  private                        dummy segment
 ~CompPrecision start
          tsc                            round to integer
          clc
-         adc     #4
-         pea     0
+         adc   #4
+         pea   0
          pha
          FRINTX
-         lda     4+8,s
+         lda   4+8,s
          pha                            save original sign
-         asl     a                      force sign to positive
-         lsr     a
-         sta     6+8,s
+         asl   a                        force sign to positive
+         lsr   a
+         sta   6+8,s
          tsc                            limit precision
          clc
-         adc     #6
-         ldy     #0
+         adc   #6
+         ldy   #0
          phy
          pha
          phy
@@ -107,10 +107,10 @@ fpextra  private                        dummy segment
          FX2C
          FC2X
          pla                            restore original sign
-         bpl     ret
-         lda     4+8,s
-         ora     #$8000
-         sta     4+8,s
+         bpl   ret
+         lda   4+8,s
+         ora   #$8000
+         sta   4+8,s
 ret      rtl
          end